I Mastered Xi Jinping Thought, and I Have the Certificate to Prove It – Foreign Policy
"There is a fundamental incompatibility between these two goals: One cannot simultaneously have world-class universities and rigid ideological servitude. Nowhere is this contradiction more glaring than in this course on Xi Jinping Thought, which gives a global community of learners an unprecedented opportunity to observe the poverty of China’s state-enforced ideology. It comes across as a cash-rich North Korea. Yet some committee decided that this particular course would be an appropriate way to introduce Tsinghua’s “world-class” education to the world. Perhaps, most likely, once the idea of offering such a course on a global platform was raised, no one at Tsinghua had the courage to raise any questions or doubts.
"Nor, of course, did edX see any problem with this. Assuming that edX has quality controls, someone there also greenlighted this empty paean to a dictator who has overseen the arrest of hundreds of human rights lawyers, the destruction of civil society, and the arbitrary and indefinite detention of more than a million Muslims in internment camps."
china  china:prc  ideology  academia  moocs 
10 hours ago
Feke, J.: Ptolemy's Philosophy: Mathematics as a Way of Life (Hardcover and eBook) | Princeton University Press
"The Greco-Roman mathematician Claudius Ptolemy is one of the most significant figures in the history of science. He is remembered today for his astronomy, but his philosophy is almost entirely lost to history. This groundbreaking book is the first to reconstruct Ptolemy’s general philosophical system—including his metaphysics, epistemology, and ethics—and to explore its relationship to astronomy, harmonics, element theory, astrology, cosmology, psychology, and theology.
"In this stimulating intellectual history, Jacqueline Feke uncovers references to a complex and sophisticated philosophical agenda scattered among Ptolemy’s technical studies in the physical and mathematical sciences. She shows how he developed a philosophy that was radical and even subversive, appropriating ideas and turning them against the very philosophers from whom he drew influence. Feke reveals how Ptolemy’s unique system is at once a critique of prevailing philosophical trends and a conception of the world in which mathematics reigns supreme.
"A compelling work of scholarship, Ptolemy’s Philosophy demonstrates how Ptolemy situated mathematics at the very foundation of all philosophy—theoretical and practical—and advanced the mathematical way of life as the true path to human perfection."
to:NB  books:noted  ptolemy  history_of_science  history_of_philosophy  ancient_history 
Data Science for Undergraduates: Opportunities and Options | The National Academies Press
"Data science is emerging as a field that is revolutionizing science and industries alike. Work across nearly all domains is becoming more data driven, affecting both the jobs that are available and the skills that are required. As more data and ways of analyzing them become available, more aspects of the economy, society, and daily life will become dependent on data. It is imperative that educators, administrators, and students begin today to consider how to best prepare for and keep pace with this data-driven era of tomorrow. Undergraduate teaching, in particular, offers a critical link in offering more data science exposure to students and expanding the supply of data science talent.
"Data Science for Undergraduates: Opportunities and Options offers a vision for the emerging discipline of data science at the undergraduate level. This report outlines some considerations and approaches for academic institutions and others in the broader data science communities to help guide the ongoing transformation of this field."
to:NB  books:noted  statistics  pedagogy 
[1805.06826] The Blessings of Multiple Causes
"Causal inference from observational data often assumes "strong ignorability," that all confounders are observed. This assumption is standard yet untestable. However, many scientific studies involve multiple causes, different variables whose effects are simultaneously of interest. We propose the deconfounder, an algorithm that combines unsupervised machine learning and predictive model checking to perform causal inference in multiple-cause settings. The deconfounder infers a latent variable as a substitute for unobserved confounders and then uses that substitute to perform causal inference. We develop theory for when the deconfounder leads to unbiased causal estimates, and show that it requires weaker assumptions than classical causal inference. We analyze its performance in three types of studies: semi-simulated data around smoking and lung cancer, semi-simulated data around genomewide association studies, and a real dataset about actors and movie revenue. The deconfounder provides a checkable approach to estimating close-to-truth causal effects."

--- ETA after skimming: This is a very cool idea, but I don't see how it could work. If we had an adequate set of controls $X$ for estimating the effect of the action $A$ on the response $Y$, we'd have $A \indep Y(a) | X$ (using the potential-outcome notation that the paper does). What they very ingeniously do is construct a _latent_ variable $Z$ s.t. $A \indep Y(a) | Z$. But we can't actually condition on $Z$, we can only condition on an _estimate_ of $Z$, say $\hat{Z}$. Since $\hat{Z}$ is a statistic and therefore a function of the observables, i.e., $A$ and $X$, its sigma-algebra is a coarsening of the sigma-algebra of the observables, $\sigma(hat(Z)) \subset \sigma(A, X)$. Hence $A \indep Y(a) | \hat{Z}$ only if $A \indep Y(a) | (A,X)$, i.e., we'd seem to need no-unmeasured-confounding to begin with. (Exception: if we've got a consistent estimator, we could make claims about _asymptotic_ de-confounding, as in https://arxiv.org/abs/1607.06565 .)
David is _much_ smarter than I am, so I am sure there is something I am missing here. I should just ask him...
to:NB  causal_inference  causal_discovery  blei.david  statistics  to_read 
3 days ago
Do the Low WHRs and BMIs Judged Most Attractive Indicate Higher Fertility? - William D. Lassek, Steven J. C. Gaulin, 2018
"We examine the widely accepted view that very low waist–hip ratios and low body mass indices (BMIs) in women in well-nourished populations are judged attractive by men because these features reliably indicate superior fertility. In both subsistence and well-nourished populations, relevant studies of fertility do not support this view. Rather studies indicate lower fertility in women with anthropometric values associated with high attractiveness. Moreover, low maternal BMI predisposes to conditions that compromise infant survival. Consistent with these findings from the literature, new data from a large U.S. sample of women past reproductive age show that women with lower BMIs in the late teens had fewer live births, controlling for education, marital history, and race. They also had later menarche and earlier menopause compared with women with higher youth BMIs. In addition, data from the 2013 U.S. natality database show that mothers with lower prepregnancy BMIs have an increased risk of producing both low-birth-weight and preterm infants controlling for other relevant variables—conditions that would have adversely affected fitness over almost all of human evolution. Thus, a review of the relevant literature and three new tests fail to support the view that highly attractive women are more fertile."
in_NB  evolutionary_psychology  practices_relating_to_the_transmission_of_genetic_information 
3 days ago
Climatic Impacts of Wind Power | The Keith Group
"We find that generating today’s US electricity demand (0.5 TWe) with wind power would warm Continental US surface temperatures by 0.24C. Warming arises, in part, from turbines redistributing heat by mixing the boundary layer. Modeled diurnal and seasonal temperature differences are roughly consistent with recent observations of warming at wind farms, reflecting a coherent mechanistic understanding for how wind turbines alter climate. The warming effect is: small compared with projections of 21st century warming, approximately equivalent to the reduced warming achieved by decarbonizing global electricity generation, and large compared with the reduced warming achieved by decarbonizing US electricity with wind. For the same generation rate, the climatic impacts from solar photovoltaic systems are about ten times smaller than wind systems. Wind’s overall environmental impacts are surely less than fossil energy. Yet, as the energy system is decarbonized, decisions between wind and solar should be informed by estimates of their climate impacts."

--- Via a student's answer to the midterm exam!
to:NB  climate_change 
4 days ago
[1810.03579] Long ties accelerate noisy threshold-based contagions
"Changes to network structure can substantially affect when and how widely new ideas, products, and conventions are adopted. In models of biological contagion, interventions that randomly rewire edges (making them "longer") accelerate spread. However, there are other models relevant to social contagion, such as those motivated by myopic best-response in games with strategic complements, in which individual's behavior is described by a threshold number of adopting neighbors above which adoption occurs (i.e., complex contagions). Recent work has argued that highly clustered, rather than random, networks facilitate spread of these complex contagions. Here we show that minor modifications of prior analyses, which make them more realistic, reverse this result. The modification is that we allow very rarely below threshold adoption, i.e., very rarely adoption occurs, where there is only one adopting neighbor. To model the trade-off between long and short edges we consider networks that are the union of cycle-power-k graphs and random graphs on n nodes. We study how the time to global spread changes as we replace the cycle edges with (random) long ties. Allowing adoptions below threshold to occur with order 1/n‾√ probability is enough to ensure that random rewiring accelerates spread. Simulations illustrate the robustness of these results to other commonly-posited models for noisy best-response behavior. We then examine empirical social networks, where we find that hypothetical interventions that (a) randomly rewire existing edges or (b) add random edges reduce time to spread compared with the original network or addition of "short", triad-closing edges, respectively. This substantially revises conclusions about how interventions change the spread of behavior, suggesting that those wanting to increase spread should induce formation of long ties, rather than triad-closing ties."
to:NB  networks  social_influence  re:do-institutions-evolve  eckles.dean  to_read 
7 days ago
Prediction Interval for Autoregressive Time Series via Oracally Efficient Estimation of Multi‐Step‐Ahead Innovation Distribution Function - Kong - 2018 - Journal of Time Series Analysis - Wiley Online Library
"A kernel distribution estimator (KDE) is proposed for multi‐step‐ahead prediction error distribution of autoregressive time series, based on prediction residuals. Under general assumptions, the KDE is proved to be oracally efficient as the infeasible KDE and the empirical cumulative distribution function (cdf) based on unobserved prediction errors. Quantile estimator is obtained from the oracally efficient KDE, and prediction interval for multi‐step‐ahead future observation is constructed using the estimated quantiles and shown to achieve asymptotically the nominal confidence levels. Simulation examples corroborate the asymptotic theory."
in_NB  prediction  time_series  statistics  kernel_estimators 
7 days ago
A Locally Optimal Algorithm for Estimating a Generating Partition from an Observed Time Series and Its Application to Anomaly Detection | Neural Computation | MIT Press Journals
"Estimation of a generating partition is critical for symbolization of measurements from discrete-time dynamical systems, where a sequence of symbols from a (finite-cardinality) alphabet may uniquely specify the underlying time series. Such symbolization is useful for computing measures (e.g., Kolmogorov-Sinai entropy) to identify or characterize the (possibly unknown) dynamical system. It is also useful for time series classification and anomaly detection. The seminal work of Hirata, Judd, and Kilminster (2004) derives a novel objective function, akin to a clustering objective, that measures the discrepancy between a set of reconstruction values and the points from the time series. They cast estimation of a generating partition via the minimization of their objective function. Unfortunately, their proposed algorithm is nonconvergent, with no guarantee of finding even locally optimal solutions with respect to their objective. The difficulty is a heuristic nearest neighbor symbol assignment step. Alternatively, we develop a novel, locally optimal algorithm for their objective. We apply iterative nearest-neighbor symbol assignments with guaranteed discrepancy descent, by which joint, locally optimal symbolization of the entire time series is achieved. While most previous approaches frame generating partition estimation as a state-space partitioning problem, we recognize that minimizing the Hirata et al. (2004) objective function does not induce an explicit partitioning of the state space, but rather the space consisting of the entire time series (effectively, clustering in a (countably) infinite-dimensional space). Our approach also amounts to a novel type of sliding block lossy source coding. Improvement, with respect to several measures, is demonstrated over popular methods for symbolizing chaotic maps. We also apply our approach to time-series anomaly detection, considering both chaotic maps and failure application in a polycrystalline alloy material."
in_NB  time_series  symbolic_dynamics  information_theory  re:AoS_project 
7 days ago
Fragmentation promotes accumulation | Philosophical Transactions of the Royal Society B: Biological Sciences
"Identifying the determinants of cumulative cultural evolution is a key issue in the interdisciplinary field of cultural evolution. A widely held view is that large and well-connected social networks facilitate cumulative cultural evolution because they promote the spread of useful cultural traits and prevent the loss of cultural knowledge through factors such as drift. This view stems from models that focus on the transmission of cultural information, without considering how new cultural traits actually arise. In this paper, we review the literature from various fields that suggest that, under some circumstances, increased connectedness can decrease cultural diversity and reduce innovation rates. Incorporating this idea into an agent-based model, we explore the effect of population fragmentation on cumulative culture and show that, for a given population size, there exists an intermediate level of population fragmentation that maximizes the rate of cumulative cultural evolution. This result is explained by the fact that fully connected, non-fragmented populations are able to maintain complex cultural traits but produce insufficient variation and so lack the cultural diversity required to produce highly complex cultural traits. Conversely, highly fragmented populations produce a variety of cultural traits but cannot maintain complex ones. In populations with intermediate levels of fragmentation, cultural loss and cultural diversity are balanced in a way that maximizes cultural complexity. Our results suggest that population structure needs to be taken into account when investigating the relationship between demography and cumulative culture."
to:NB  to_read  cultural_evolution  diversity  social_networks  re:democratic_cognition  re:do-institutions-evolve  via:hugo_mercier 
7 days ago
Tunnel Visions: The Rise and Fall of the Superconducting Super Collider, Riordan, Hoddeson, Kolb
"Starting in the 1950s, US physicists dominated the search for elementary particles; aided by the association of this research with national security, they held this position for decades. In an effort to maintain their hegemony and track down the elusive Higgs boson, they convinced President Reagan and Congress to support construction of the multibillion-dollar Superconducting Super Collider project in Texas—the largest basic-science project ever attempted. But after the Cold War ended and the estimated SSC cost surpassed ten billion dollars, Congress terminated the project in October 1993.
"Drawing on extensive archival research, contemporaneous press accounts, and over one hundred interviews with scientists, engineers, government officials, and others involved, Tunnel Visions tells the riveting story of the aborted SSC project. The authors examine the complex, interrelated causes for its demise, including problems of large-project management, continuing cost overruns, and lack of foreign contributions. In doing so, they ask whether Big Science has become too large and expensive, including whether academic scientists and their government overseers can effectively manage such an enormous undertaking."
to:NB  books:noted  history_of_science  history_of_physics  particle_physics 
8 days ago
Enchanted America: How Intuition and Reason Divide Our Politics, Oliver, Wood
"America is in civic chaos, its politics rife with conspiracy theories and false information.  Nationalism and authoritarianism are on the rise, while scientists, universities, and news organizations are viewed with increasing mistrust. Its citizens reject scientific evidence on climate change and vaccinations while embracing myths of impending apocalypse. And then there is Donald Trump, a presidential candidate who won the support of millions of conservative Christians despite having no moral or political convictions. What is going on?
"The answer, according to J. Eric Oliver and Thomas J. Wood, can be found in the most important force shaping American politics today: human intuition. Much of what seems to be irrational in American politics arises from the growing divide in how its citizens make sense of the world. On one side are rationalists. They use science and reason to understand reality. On the other side are intuitionists. They rely on gut feelings and instincts as their guide to the world. Intuitionists believe in ghosts and End Times prophecies. They embrace conspiracy theories, disbelieve experts, and distrust the media.  They are stridently nationalistic and deeply authoritarian in their outlook. And they are the most enthusiastic supporters of Donald Trump. The primary reason why Trump captured the presidency was that he spoke about politics in a way that resonated with how Intuitionists perceive the world. The Intuitionist divide has also become a threat to the American way of life. A generation ago, intuitionists were dispersed across the political spectrum, when most Americans believed in both God and science. Today, intuitionism is ideologically tilted toward the political right. Modern conservatism has become an Intuitionist movement, defined by conspiracy theories, strident nationalism, and hostility to basic civic norms. 
"Enchanted America is a clarion call to rationalists of all political persuasions to reach beyond the minority and speak to intuitionists in a way they understand.  The values and principles that define American democracy are at stake. "

--- I am _a priori_ skeptical about the thesis that "intuitionists" are ideologically concentrated. (Also, that's not _intuition_, which would be individual and not socially shared...)
to:NB  books:noted  us_politics  our_decrepit_institutions  anti-intellectualism_in_american_life  to_be_shot_after_a_fair_trial 
8 days ago
Helmholtz: A Life in Science, Cahan
"Hermann von Helmholtz was a towering figure of nineteenth-century scientific and intellectual life. Best known for his achievements in physiology and physics, he also contributed to other disciplines such as ophthalmology, psychology, mathematics, chemical thermodynamics, and meteorology. With Helmholtz: A Life in Science, David Cahan has written a definitive biography, one that brings to light the dynamic relationship between Helmholtz’s private life, his professional pursuits, and the larger world in which he lived.
​"Utilizing all of Helmholtz’s scientific and philosophical writings, as well as previously unknown letters, this book reveals the forces that drove his life—a passion to unite the sciences, vigilant attention to the sources and methods of knowledge, and a deep appreciation of the ways in which the arts and sciences could benefit each other. By placing the overall structure and development of his scientific work and philosophy within the greater context of nineteenth-century Germany, Helmholtz also serves as cultural biography of the construction of the scientific community: its laboratories, institutes, journals, disciplinary organizations, and national and international meetings. Helmholtz’s life is a shining example of what can happen when the sciences and the humanities become interwoven in the life of one highly motivated, energetic, and gifted person."
to:NB  books:noted  lives_of_the_scientists  history_of_science  helmholtz.hermann 
8 days ago
[1809.05651] Omitted and Included Variable Bias in Tests for Disparate Impact
"Policymakers often seek to gauge discrimination against groups defined by race, gender, and other protected attributes. One popular strategy is to estimate disparities after controlling for observed covariates, typically with a regression model. This approach, however, suffers from two statistical challenges. First, omitted-variable bias can skew results if the model does not control for all relevant factors; second, and conversely, included-variable bias can skew results if the set of controls includes irrelevant factors. Here we introduce a simple three-step strategy---which we call risk-adjusted regression---that addresses both concerns in settings where decision makers have clearly measurable objectives. In the first step, we use all available covariates to estimate the utility of possible decisions. In the second step, we measure disparities after controlling for these utility estimates alone, mitigating the problem of included-variable bias. Finally, in the third step, we examine the sensitivity of results to unmeasured confounding, addressing concerns about omitted-variable bias. We demonstrate this method on a detailed dataset of 2.2 million police stops of pedestrians in New York City, and show that traditional statistical tests of discrimination can yield misleading results. We conclude by discussing implications of our statistical approach for questions of law and policy."
to:NB  to_read  discrimination  racism  regression  statistics  goel.sharad 
8 days ago
Why Learn History (When It’s Already on Your Phone), Wineburg
"Let’s start with two truths about our era that are so inescapable as to have become clichés: We are surrounded by more readily available information than ever before. And a huge percentage of it is inaccurate. Some of the bad info is well-meaning but ignorant. Some of it is deliberately deceptive. All of it is pernicious.
"With the internet always at our fingertips, what’s a teacher of history  to do? Sam Wineburg has answers, beginning with this: We definitely can’t stick to the same old read-the-chapter-answer-the-questions-at-the-back snoozefest we’ve subjected students to for decades. If we want to educate citizens who can sift through the mass of information around them and separate fact from fake, we have to explicitly work to give them the necessary critical thinking tools. Historical thinking, Wineburg shows us in Why Learn History (When It’s Already on Your Phone), has nothing to do with test prep–style ability to memorize facts. Instead, it’s an orientation to the world that we can cultivate, one that encourages reasoned skepticism, discourages haste, and counters our tendency to confirm our biases. Wineburg draws on surprising discoveries from an array of research and experiments—including surveys of students, recent attempts to update history curricula, and analyses of how historians, students, and even fact checkers approach online sources—to paint a picture of a dangerously mine-filled landscape, but one that, with care, attention, and awareness, we can all learn to navigate."
to:NB  books:noted  history  networked_life  natural_history_of_truthiness  uses_of_the_past  historiography  education  epidemiology_of_representations 
8 days ago
The Worldmakers: Global Imagining in Early Modern Europe, Ramachandran
"In this beautifully conceived book, Ayesha Ramachandran reconstructs the imaginative struggles of early modern artists, philosophers, and writers to make sense of something that we take for granted: the world, imagined as a whole. Once a new, exciting, and frightening concept, “the world” was transformed in the sixteenth and seventeenth centuries. But how could one envision something that no one had ever seen in its totality?
"The Worldmakers moves beyond histories of globalization to explore how “the world” itself—variously understood as an object of inquiry, a comprehensive category, and a system of order—was self-consciously shaped by human agents. Gathering an international cast of characters, from Dutch cartographers and French philosophers to Portuguese and English poets, Ramachandran describes a history of firsts: the first world atlas, the first global epic, the first modern attempt to develop a systematic natural philosophy—all part of an effort by early modern thinkers to capture “the world” on the page."
to:NB  books:noted  early_modern_european_history  history_of_ideas  great_transformation  modernity 
8 days ago
Free Public Transit: And Why We Don’t Pay to Ride Elevators, Prince, Dellheim
"Just like we don't pay to use elevators, this book argues that we shouldn't pay to ride public transit. In an age of increasing inequalities and ecological crisis, movements advocating free public transit push us to rethink the status quo and consider urban transit as a fundamental human right. Editors Jason Prince and Judith Dellheim have collected a panorama of case studies from around the world: the United States, Canada, Estonia, Greece, France, Italy, Sweden, Poland, China, Australia, Brazil, Mexico, and more. These movements are spread across the world, and they aim to achieve two main outcomes—ecological good and fair wealth distribution. Free public transit—coupled with increased capacity and improving service of public transit—might well be the only viable strategy to eliminating car usage and achieving greenhouse gas targets in industrialized cities within a reasonable timeframe. Movements for free mass transit also aim to see public transit treated as a public good, like water and garbage service, that should be paid for out of general tax revenues or a fairer regional tax strategy. This book covers the rapidly changing transport options in cities today, including bike and car share options, Uber and Lyft, and the imminent arrival of driver-less vehicles. The first English-language book ever written on the subject, Free Public Transit is a ground breaking book for those concerned about the future of our cities and an essential resource for those who make, or try to change, urban planning and transport policies."
to:NB  books:noted  transit 
8 days ago
Seeing Green: The Use and Abuse of American Environmental Images, Dunaway
"American environmentalism is defined by its icons: the “Crying Indian,” who shed a tear in response to litter and pollution; the cooling towers of Three Mile Island, site of a notorious nuclear accident; the sorrowful spectacle of oil-soaked wildlife following the ExxonValdez spill; and, more recently, Al Gore delivering his global warming slide show in An Inconvenient Truth. These images, and others like them, have helped make environmental consciousness central to American public culture. Yet most historical accounts ignore the crucial role images have played in the making of popular environmentalism, let alone the ways that they have obscured other environmental truths.
"Finis Dunaway closes that gap with Seeing Green. Considering a wide array of images—including pictures in popular magazines, television news, advertisements, cartoons, films, and political posters—he shows how popular environmentalism has been entwined with mass media spectacles of crisis. Beginning with radioactive fallout and pesticides during the 1960s and ending with global warming today, he focuses on key moments in which media images provoked environmental anxiety but also prescribed limited forms of action. Moreover, he shows how the media have blamed individual consumers for environmental degradation and thus deflected attention from corporate and government responsibility. Ultimately, Dunaway argues, iconic images have impeded efforts to realize—or even imagine—sustainable visions of the future."
to:NB  books:noted  american_history  environmentalism  iconology  art_history 
8 days ago
Islamic Shangri-La by David G. Atwill - Paperback - University of California Press
"Islamic Shangri-La transports readers to the heart of the Himalayas as it traces the rise of the Tibetan Muslim community from the 17th century to the present. Radically altering popular interpretations that have portrayed Tibet as isolated and monolithically Buddhist, David Atwill's vibrant account demonstrates how truly cosmopolitan Tibetan society was by highlighting the hybrid influences and internal diversity of Tibet. In its exploration of the Tibetan Muslim experience, this book presents an unparalleled perspective of Tibet's standing during the rise of post–World War II Asia."
to:NB  books:noted  history  central_asia  tibet  islamic_civilization  cultural_exchange 
8 days ago
Revolution and Cosmopolitanism by Joseph Levenson - Paperback - University of California Press
"In 1965, Joseph R. Levenson began working on a new trilogy to follow his earlier study of modern Chinese intellectual history, Confucian China and Its Modern Fate. By 1969, he had already sketched out basic outlines of the work, which was to be called Provincialism, Nationalism, and Cosmopolitanism. It was to consist of three volumes: one sounding the general themes of the arrangement, and two other elaborating its motifs. Accidental death tragically cut short Levenson's life and the preparation of the work. He did leave behind, however, an embryo of it in the form of this book, Revolution and Cosmopolitanism. Based upon a careful analysis of a wide selection of Western plays translated into Chinese during the twentieth century, Revolution and Cosmopolitanism tries to set the Communist Cultural Revolution into a new kind of historical perspective. Beginning with the demise of a Confucian China which "new youth" intellectuals found too provincial for their palates, Levenson shows how those same cosmopolitans in the 1920s and 1920s damed later Communist intellectuals of the 1950s for being to receptive to non-Chinese values. As Red Guards attacked symbols of a feudal Confucian past and a bourgeois foreign present, China slipped into a new sort of provincialism. Levenson analyzes their transformation with profound subtlety. Convinced that revolutionary China cannot forever seal itself off from universal cosmopolitan influences, he expresses sympathy throughout with the dilemma of rootless intellectuals in a society searching for a particular non-intellectual identity. "

--- Levenson's _Confucian China and Its Modern Fate_ is brilliant and somehow I'd never heard of this.
to:NB  books:noted  history_of_ideas  china:prc  levenson.joseph_r.  intellectuals  cultural_revolution  nationalism  cosmopolitanism 
8 days ago
Deadly Quarrels by David Wilkinson - Paperback - University of California Press
"Lewis Fry Richardson was one of the first to develop the systematic study of the causes of war; yet his great war data archive, Statistics of Deadly Quarrels, posthumously published, has yet to be fully systematized and assimilated by war-causation scholars. David Wilkinson has reanalyzed Richardson's data and drawn together the results of kindred quantitative work on the causes of war, from other as well as from Richardson. He has translated this classic of international relations literature into contemporary idiom, fully and accurately presenting the substance of Richardson's idea and at the same time bringing it up to date with judicious comment, updating the references to the critical and successor literature, and dealing in some detail with Richardson himself. Professor Wilkinson lists among the findings: 1. the death toll of war is largely the product of a very few immense wars; 2. most wars do not escalate out of control, they are vey likely to be small, brief, and exclusive; 3. great powers have done most of the world's fighting, inflicting and suffering most of the casualties; 4. the propensity of any two groups to fight increases as the ethnocultural differences between them increase. Contemporary peace strategy would therefore seem to be to avoid World War III by promoting superpower detente, and reanimating, accelerating, and civilizing the process of world economic development.
"This title is part of UC Press's Voices Revived program, which commemorates University of California Press’s mission to seek out and cultivate the brightest minds and give them voice, reach, and impact. Drawing on a backlist dating to 1893, Voices Revived makes high-quality, peer-reviewed scholarship accessible once again using print-on-demand technology. This title was originally published in 1980."
to:NB  violence  war  heavy_tails  lives_of_the_scholars  books:noted 
8 days ago
[1706.04317] Schema Networks: Zero-shot Transfer with a Generative Causal Model of Intuitive Physics
"The recent adaptation of deep neural network-based methods to reinforcement learning and planning domains has yielded remarkable progress on individual tasks. Nonetheless, progress on task-to-task transfer remains limited. In pursuit of efficient and robust generalization, we introduce the Schema Network, an object-oriented generative physics simulator capable of disentangling multiple causes of events and reasoning backward through causes to achieve goals. The richly structured architecture of the Schema Network can learn the dynamics of an environment directly from data. We compare Schema Networks with Asynchronous Advantage Actor-Critic and Progressive Networks on a suite of Breakout variations, reporting results on training efficiency and zero-shot generalization, consistently demonstrating faster, more robust learning and better transfer. We argue that generalizing from limited data and learning causal relationships are essential abilities on the path toward generally intelligent systems"
in_NB  artificial_intelligence  reinforcement_learning  graphical_models  heard_the_talk 
8 days ago
The materiality of mathematics
"This paper explores how writing mathematics (on paper, blackboards, or even in the air) is indispensable for doing and thinking mathematics. The paper is based on video recordings of lectures in formal logic and investigates how mathematics is presented at the blackboard. The paper discusses the iconic character of blackboards in mathematics and describes in detail a number of inscription practices of presenting mathematics at the blackboard (such as the use of lines and boxes, the designation of particular regions for specific mathematical purposes, as well as creating an ‘architecture’ visualising the overall structure of the proof). The paper argues that doing mathematics really is “thinking with eyes and hands” (Latour, 1986). Thinking in mathematics is inextricably interwoven with writing mathematics."
to:NB  sociology  mathematics 
8 days ago
Generalized least squares can overcome the critical threshold in respondent-driven sampling | PNAS
"To sample marginalized and/or hard-to-reach populations, respondent-driven sampling (RDS) and similar techniques reach their participants via peer referral. Under a Markov model for RDS, previous research has shown that if the typical participant refers too many contacts, then the variance of common estimators does not decay like O(n−1)"
, where n is the sample size. This implies that confidence intervals will be far wider than under a typical sampling design. Here we show that generalized least squares (GLS) can effectively reduce the variance of RDS estimates. In particular, a theoretical analysis indicates that the variance of the GLS estimator is O(n−1)
. We then derive two classes of feasible GLS estimators. The first class is based upon a Degree Corrected Stochastic Blockmodel for the underlying social network. The second class is based upon a rank-two model. It might be of independent interest that in both model classes, the theoretical results show that it is possible to estimate the spectral properties of the population network from a random walk sample of the nodes. These theoretical results point the way to entirely different classes of estimators that account for the network structure beyond node degree. Diagnostic plots help to identify situations where feasible GLS estimators are more appropriate. The computational experiments show the potential benefits and also indicate that there is room to further develop these estimators in practical settings.
in_NB  respondent-driven_sampling  regression  rohe.karl  network_data_analysis  statistics 
9 days ago
Jackknife approach to the estimation of mutual information | PNAS
"Quantifying the dependence between two random variables is a fundamental issue in data analysis, and thus many measures have been proposed. Recent studies have focused on the renowned mutual information (MI) [Reshef DN, et al. (2011) Science 334:1518–1524]. However, “Unfortunately, reliably estimating mutual information from finite continuous data remains a significant and unresolved problem” [Kinney JB, Atwal GS (2014) Proc Natl Acad Sci USA 111:3354–3359]. In this paper, we examine the kernel estimation of MI and show that the bandwidths involved should be equalized. We consider a jackknife version of the kernel estimate with equalized bandwidth and allow the bandwidth to vary over an interval. We estimate the MI by the largest value among these kernel estimates and establish the associated theoretical underpinnings."
in_NB  entropy_estimation  statistics 
9 days ago
How to play 20 questions with nature and lose: Reflections on 100 years of brain-training research | PNAS
"Despite dozens of empirical studies and a growing body of meta-analytic work, there is little consensus regarding the efficacy of cognitive training. In this review, we examine why this substantial corpus has failed to answer the often-asked question, “Does cognitive training work?” We first define cognitive training and discuss the general principles underlying training interventions. Next, we review historical interventions and discuss how findings from this early work remain highly relevant for current cognitive-training research. We highlight a variety of issues preventing real progress in understanding the underlying mechanisms of training, including the lack of a coherent theoretical framework to guide training research and methodological issues across studies and meta-analyses. Finally, suggestions for correcting these issues are offered in the hope that we might make greater progress in the next 100 y of cognitive-training research."
to:NB  cognitive_development  psychology  history_of_science  to_read 
9 days ago
Narrating ethnicity and diversity in Middle Eastern national genome projects - Elise K Burton, 2018
"Most Middle Eastern populations outside Israel have not been represented in Western-based international human genome sequencing efforts. In response, national-level projects have emerged throughout the Middle East to decode the Arab, Turkish and Iranian genomes. The discourses surrounding the ‘national genome’ that shape scientists’ representation of their work to local and international audiences evoke three intersecting analytics of nationalism: methodological, postcolonial and diasporic. Methodologically, ongoing human genome projects in Turkey and Iran follow the population logics of other national and international genome projects, for example justifying research with reference to projected health benefits to their fellow citizens. Meanwhile, assumptions about and representations of ethnicity and diversity are deeply inflected by local histories of scientific development and nationalist politics. While Iranian geneticists have transformed this paradigm to catalog national genetic diversity through a discourse of ‘Iranian ethnicities’, Turkish geneticists remain politically constrained from acknowledging ethnic diversity and struggle to distance their work from racialized narratives of Turkish national identity. Such nationally-framed narratives of genomic diversity are not confined to their original contexts, but travel abroad, as demonstrated by a US-based genome project that articulates a form of Iranian-American diasporic nationalism."
to:NB  human_genetics  nationalism  iran  turkey 
9 days ago
Artificial Intelligence: Foundations of Computational Agents, 2e
"Artificial Intelligence: Foundations of Computational Agents, second edition, Cambridge University Press 2017, is a book about the science of artificial intelligence (AI). It presents artificial intelligence as the study of the design of intelligent computational agents. The book is structured as a textbook, but it is accessible to a wide audience of professionals and researchers. In the last decades we have witnessed the emergence of artificial intelligence as a serious science and engineering discipline. This book provides an accessible synthesis of the field aimed at undergraduate and graduate students. It provides a coherent vision of the foundations of the field as it is today. It aims to provide that synthesis as an integrated science, in terms of a multi-dimensional design space that has been partially explored. As with any science worth its salt, artificial intelligence has a coherent, formal theory and a rambunctious experimental wing. The book balances theory and experiment, showing how to link them intimately together. It develops the science of AI together with its engineering applications."
in_NB  to_browse  artificial_intelligence 
9 days ago
[1804.05296] Adversarial Attacks Against Medical Deep Learning Systems
"The discovery of adversarial examples has raised concerns about the practical deployment of deep learning systems. In this paper, we argue that the field of medicine may be uniquely susceptible to adversarial attacks, both in terms of monetary incentives and technical vulnerability. To this end, we outline the healthcare economy and the incentives it creates for fraud, we extend adversarial attacks to three popular medical imaging tasks, and we provide concrete examples of how and why such attacks could be realistically carried out. For each of our representative medical deep learning classifiers, both white and black box attacks were highly successful. We urge caution in deploying deep learning systems in clinical settings, and encourage the machine learning community to further investigate the domain-specific characteristics of medical learning systems."
in_NB  to_read  adversarial_examples  neural_networks  your_favorite_deep_neural_network_sucks  via:melanie_mitchell 
9 days ago
[1709.05862] Recognizing Objects In-the-wild: Where Do We Stand?
"The ability to recognize objects is an essential skill for a robotic system acting in human-populated environments. Despite decades of effort from the robotic and vision research communities, robots are still missing good visual perceptual systems, preventing the use of autonomous agents for real-world applications. The progress is slowed down by the lack of a testbed able to accurately represent the world perceived by the robot in-the-wild. In order to fill this gap, we introduce a large-scale, multi-view object dataset collected with an RGB-D camera mounted on a mobile robot. The dataset embeds the challenges faced by a robot in a real-life application and provides a useful tool for validating object recognition algorithms. Besides describing the characteristics of the dataset, the paper evaluates the performance of a collection of well-established deep convolutional networks on the new dataset and analyzes the transferability of deep representations from Web images to robotic data. Despite the promising results obtained with such representations, the experiments demonstrate that object classification with real-life robotic data is far from being solved. Finally, we provide a comparative study to analyze and highlight the open challenges in robot vision, explaining the discrepancies in the performance."
to:NB  machine_learning  neural_networks  your_favorite_deep_neural_network_sucks  classifiers  to_read  via:melanie_mitchell 
9 days ago
Fast brief practical DFA minimization - ScienceDirect
"Minimization of deterministic finite automata has traditionally required complicated programs and correctness proofs, and taken
time, where n is the number of states and k the size of the alphabet. Here a short, memory-efficient program is presented that runs in
, or even in
, time, where m is the number of transitions. The program is complete with input, output, and the removal of irrelevant parts of the automaton. Its invariant-style correctness proof is relatively short."
in_NB  automata_theory  re:AoS_project  to_read  via:? 
12 days ago
Witch | Yale University Press
"The witch came to prominence—and often a painful death—in early modern Europe, yet her origins are much more geographically diverse and historically deep. In this landmark book, Ronald Hutton traces witchcraft from the ancient world to the early-modern stake.
"This book sets the notorious European witch trials in the widest and deepest possible perspective and traces the major historiographical developments of witchcraft. Hutton, a renowned expert on ancient, medieval, and modern paganism and witchcraft beliefs, combines Anglo-American and continental scholarly approaches to examine attitudes on witchcraft and the treatment of suspected witches across the world, including in Africa, the Middle East, South Asia, Australia, and North and South America, and from ancient pagan times to current interpretations. His fresh anthropological and ethnographical approach focuses on cultural inheritance and change while considering shamanism, folk religion, the range of witch trials, and how the fear of witchcraft might be eradicated."
in_NB  books:noted  witches  history_of_ideas  history_of_religion  epidemiology_of_representations  hutton.ronald 
14 days ago
Haunted | Yale University Press
"Continuing his interest in the history of emotion, this book explores how fear has been shaped into images of monsters and monstrosity. From the Protestant Reformation to contemporary horror films and fiction, he explores four major types: the monster from nature (King Kong), the created monster (Frankenstein), the monster from within (Mr. Hyde), and the monster from the past (Dracula). Drawing upon deep historical and literary research, Braudy discusses the lasting presence of fearful imaginings in an age of scientific progress, viewing the detective genre as a rational riposte to the irrational world of the monstrous. Haunted is a compelling and incisive work by a writer at the height of his powers."
to:NB  books:noted  mythology  horror  literary_history 
14 days ago
Science and the Good | Yale University Press
"In this illuminating book, James Davison Hunter and Paul Nedelisky recount the centuries-long, passionate quest to discover a scientific foundation for morality. The "new moral science" led by such figures as E.O. Wilson, Patricia Churchland and Joshua Greene is only the newest manifestation of an effort that has failed repeatedly. Though claims for its accomplishments are often wildly exaggerated, this new iteration has been no more successful than its predecessors. Hunter and Nedelisky argue that in the end, science cannot tell us how we should live or why we should be good and not evil, and this is for both philosophical and scientific reasons.  
"In the face of this failure, the new moral science has taken a surprising turn. Whereas earlier efforts sought to demonstrate what is right and wrong, the new moral scientists have concluded that right and wrong, because they are not amenable to scientific study, don’t actually exist. Their (perhaps unwitting) moral nihilism turns the science of morality into a social engineering project. If there is nothing moral for science to discover, the science of morality becomes, at best, a program to achieve arbitrary societal goals."
to:NB  books:noted  ethics  history_of_ideas 
14 days ago
Responsible Parties | Yale University Press
"In recent decades, democracies across the world have adopted measures to increase popular involvement in political decisions. Parties have turned to primaries and local caucuses to select candidates; ballot initiatives and referenda allow citizens to enact laws directly; many places now use proportional representation, encouraging smaller, more specific parties rather than two dominant ones.Yet voters keep getting angrier.There is a steady erosion of trust in politicians, parties, and democratic institutions, culminating most recently in major populist victories in the United States, the United Kingdom, and elsewhere.
"Frances Rosenbluth and Ian Shapiro argue that devolving power to the grass roots is part of the problem. Efforts to decentralize political decision-making have made governments and especially political parties less effective and less able to address constituents’ long-term interests. They argue that to restore confidence in governance, we must restructure our political systems to restore power to the core institution of representative democracy: the political party."
to:NB  books:noted  political_science  democracy  re:democratic_cognition  shapiro.ian 
14 days ago
Vampire | Yale University Press
"Published to mark the bicentenary of John Polidori’s publication of The Vampyre, Nick Groom’s detailed new account illuminates the complex history of the iconic creature. The vampire first came to public prominence in the early eighteenth century, when Enlightenment science collided with Eastern European folklore and apparently verified outbreaks of vampirism, capturing the attention of medical researchers, political commentators, social theorists, theologians, and philosophers. Groom accordingly traces the vampire from its role as a monster embodying humankind’s fears, to that of an unlikely hero for the marginalized and excluded in the twenty-first century.
"Drawing on literary and artistic representations, as well as medical, forensic, empirical, and sociopolitical perspectives, this rich and eerie history presents the vampire as a strikingly complex being that has been used to express the traumas and contradictions of the human condition."
to:NB  books:noted  mythology  history_of_ideas  literary_history  vampires 
14 days ago
rWind package on CRAN
For access to wind velocity data sets. (Surprisingly slow access, but very glad somebody has written this so I don't have to!)

--- ETA: The server they're yanking the data from is very temperamental, and grabbing a long temporal stretch is almost sure to fail. But grabbing about 30 days of data at a time seems OK.
R  data_sets  to_teach:data_over_space_and_time 
14 days ago
On the Sensitivity of Granger Causality to Errors‐In‐Variables, Linear Transformations and Subsampling - Anderson - - Journal of Time Series Analysis - Wiley Online Library
"This article studies the sensitivity of Granger causality to the addition of noise, the introduction of subsampling, and the application of causal invertible filters to weakly stationary processes. Using canonical spectral factors and Wold decompositions, we give general conditions under which additive noise or filtering distorts Granger‐causal properties by inducing (spurious) Granger causality, as well as conditions under which it does not. For the errors‐in‐variables case, we give a continuity result, which implies that: a ‘small’ noise‐to‐signal ratio entails ‘small’ distortions in Granger causality. On filtering, we give general necessary and sufficient conditions under which ‘spurious’ causal relations between (vector) time series are not induced by linear transformations of the variables involved. This also yields transformations (or filters) which can eliminate Granger causality from one vector to another one. In a number of cases, we clarify results in the existing literature, with a number of calculations streamlining some existing approaches."
to:NB  time_series  prediction  granger_causality  measurement 
18 days ago
[1809.10302] The hidden traits of endemic illiteracy in cities
"In spite of the considerable progress towards reducing illiteracy rates, many countries, including developed ones, have encountered difficulty achieving further reduction in these rates. This is worrying because illiteracy has been related to numerous health, social, and economic problems. Here, we show that the spatial patterns of illiteracy in urban systems have several features analogous to the spread of diseases such as dengue and obesity. Our results reveal that illiteracy rates are spatially long-range correlated, displaying non-trivial clustering structures characterized by percolation-like transitions and fractality. These patterns can be described in the context of percolation theory of long-range correlated systems at criticality. Together, these results provide evidence that the illiteracy incidence can be related to a transmissible process, in which the lack of access to minimal education propagates in a population in a similar fashion to endemic diseases."

--- Of course it's coming out in _Physica A_.
to:NB  sociology  to_be_shot_after_a_fair_trial  social_influence  re:homophily_and_confounding 
18 days ago
Estimating Group Effects Using Averages of Observables to Control for Sorting on Unobservables: School and Neighborhood Effects
"We consider the classic problem of estimating group treatment effects when individuals sort based on observed and unobserved characteristics. Using a standard choice model, we show that controlling for group averages of observed individual characteristics potentially absorbs all the across-group variation in unobservable individual characteristics. We use this insight to bound the treatment effect variance of school systems and associated neighborhoods for various outcomes. Across multiple datasets, we find that a 90th versus 10th percentile school/neighborhood increases the high school graduation probability and college enrollment probability by at least 0.04 and 0.11 and permanent wages by 13.7 percent."

--- This sounds bogus, or at least question-begging, to me. ("If you assume that unobserved characteristics can be perfectly tracked by observed characteristics, you don't need to worry about unobserved characteristics" --- not an actual quote.) The last tag applies.
to:NB  social_influence  causal_inference  to_be_shot_after_a_fair_trial 
21 days ago
Why Do Defaults Affect Behavior? Experimental Evidence from Afghanistan
"We report on an experiment examining why default options impact behavior. By randomly assigning employees to different varieties of a salary-linked savings account, we find that default enrollment increases participation by 40 percentage points—an effect equivalent to providing a 50% matching incentive. We then use a series of experimental interventions to differentiate between explanations for the default effect, which we conclude is driven largely by present-biased preferences and the cognitive cost of thinking through different savings scenarios. Default assignment also changes employees' attitudes toward saving, and makes them more likely to actively decide to save after the study concludes."
to:NB  economics  experimental_economics  re:anti-nudge  afghanistan 
21 days ago
Physical Computation - Paperback - Gualtiero Piccinini - Oxford University Press
"Gualtiero Piccinini articulates and defends a mechanistic account of concrete, or physical, computation. A physical system is a computing system just in case it is a mechanism one of whose functions is to manipulate vehicles based solely on differences between different portions of the vehicles according to a rule defined over the vehicles. Physical Computation discusses previous accounts of computation and argues that the mechanistic account is better. Many kinds of computation are explicated, such as digital vs. analog, serial vs. parallel, neural network computation, program-controlled computation, and more. Piccinini argues that computation does not entail representation or information processing although information processing entails computation. Pancomputationalism, according to which every physical system is computational, is rejected. A modest version of the physical Church-Turing thesis, according to which any function that is physically computable is computable by Turing machines, is defended."
to:NB  books:noted  via:rvenkat  computation  dynamical_systems  explanation_by_mechanisms 
21 days ago
Overlooked factors in the analysis of parole decisions | PNAS
"Danziger et al. (1) concluded that meal breaks taken by Israeli parole boards influence the boards’ decisions. This conclusion depends on the order of cases being random or at least exogenous to the timing of meal breaks. We examined data provided by the authors and obtained additional data from 12 hearing days (n = 227 decisions).* We also interviewed three attorneys, a parole panel judge, and five personnel at Israeli Prison Services and Court Management, learning that case ordering is not random and that several factors contribute to the downward trend in prisoner success between meal breaks. The most important is that the board tries to complete all cases from one prison before it takes a break and to start with another prison after the break. Within each session, unrepresented prisoners usually go last and are less likely to be granted parole than prisoners with attorneys. Using the same decision rules as Danziger et al., our data indicate that unrepresented prisoners account for about one-third of all cases, but they prevail only 15% of the time, whereas prisoners with counsel prevail at a 35% rate.
"This nonrandom order of cases might have become apparent had the authors not limited their analysis. They lumped together decisions rejecting parole and cases that were deferred to a later date. Theoretically and in practice, deferrals are not comparable to rejections of parole.
"Excluding these deferred cases, our data indicate a success rate of 67% for prisoners with counsel and 39% for unrepresented prisoners. Excluding deferrals in the authors' data yields very similar success rates, beginning at about 75% and dropping to 42% at the end of a session. Thus, we strongly suspect that the pattern of declining success rates is a result of hearing represented prisoners first and unrepresented prisoners last...."
psychology  via:?  bad_data_analysis 
22 days ago
Lognormal-de Wijsian Geostatistics for Ore Evaluation
Krige on kriging. I have to admit I hadn't fully realized that the historical context was "keep South Africa going"...
in_NB  have_read  spatial_statistics  prediction  statistics  geology  to_teach:data_over_space_and_time 
24 days ago
Some Methodological Problems in the Study of Multigenerational Mobility | European Sociological Review | Oxford Academic
"A number of recent studies by sociologists have sought to discover whether a person’s status (typically their social class, education, or socio-economic status) is directly affected by the status of their grandparents, once the effects of parents’ status are controlled. The results have been ambiguous, with some studies finding a direct effect of grandparents on their grandchildren, while others find no effect. I use causal graphical methods to demonstrate some of the methodological problems that occur in trying to identify this direct effect, and I offer some suggestions as to how they might be addressed."
to:NB  sociology  causal_inference  inequality  transmission_of_inequality  graphical_models  via:? 
24 days ago
[math/0506080] Two new Markov order estimators
"We present two new methods for estimating the order (memory depth) of a finite alphabet Markov chain from observation of a sample path. One method is based on entropy estimation via recurrence times of patterns, and the other relies on a comparison of empirical conditional probabilities. The key to both methods is a qualitative change that occurs when a parameter (a candidate for the order) passes the true order. We also present extensions to order estimation for Markov random fields."
in_NB  markov_models  statistical_inference_for_stochastic_processes  model_selection  recurrence_times  entropy_estimation  information_theory  stochastic_processes  have_read  have_talked_about  random_fields 
25 days ago
A study exploring the impact of lecture capture availability and lecture capture usage on student attendance and attainment | SpringerLink
"Lecture capture is widely used within higher education as a means of recording lecture material for online student viewing. However, there is some uncertainty around whether this is a uniformly positive development for students. The current study examines the impact of lecture capture introduction and usage in a compulsory second year research methods module in a undergraduate BSc degree. Data collected from a matched cohort before (N = 161) and after (N = 160) lecture capture introduction showed that attendance substantially dropped in three matched lectures after capture became available. Attendance, which predicts higher attainment (controlling for students’ previous grade and gender), mediates a negative relationship between lecture capture availability and attainment. Lecture capture viewing shows no significant relationship with attainment whilst factoring in lecture attendance; capture viewing also fails to compensate for the impact that low attendance has on attainment. Thus, the net effect of lecture capture introduction on the cohort is generally negative; the study serves as a useful example (that can be communicated students) of the pitfalls of an over-reliance on lecture capture as a replacement for lecture attendance."

--- tl;dr: Butts in seats rules, OK?
education  pedagogy  via:jbdelong  i_want_to_believe 
28 days ago
A personal essay on Bayes factors
I would have said nobody blogs like this anymore, and I am very happy to be very wrong.
have_read  model_selection  bayesianism  statistics  psychology  social_science_methodology  via:tslumley 
29 days ago
Making it easier to discover datasets
Data set search; not sure how well it really works yet (or how long it will live, before Google breaks it. [Why, yes, I am still bitter about Reader.])
data_sets  to_teach 
29 days ago
[1809.02512] Multi-level hypothesis testing for populations of heterogeneous networks
"In this work, we consider hypothesis testing and anomaly detection on datasets where each observation is a weighted network. Examples of such data include brain connectivity networks from fMRI flow data, or word co-occurrence counts for populations of individuals. Current approaches to hypothesis testing for weighted networks typically requires thresholding the edge-weights, to transform the data to binary networks. This results in a loss of information, and outcomes are sensitivity to choice of threshold levels. Our work avoids this, and we consider weighted-graph observations in two situations, 1) where each graph belongs to one of two populations, and 2) where entities belong to one of two populations, with each entity possessing multiple graphs (indexed e.g. by time). Specifically, we propose a hierarchical Bayesian hypothesis testing framework that models each population with a mixture of latent space models for weighted networks, and then tests populations of networks for differences in distribution over components. Our framework is capable of population-level, entity-specific, as well as edge-specific hypothesis testing. We apply it to synthetic data and three real-world datasets: two social media datasets involving word co-occurrences from discussions on Twitter of the political unrest in Brazil, and on Instagram concerning Attention Deficit Hyperactivity Disorder (ADHD) and depression drugs, and one medical dataset involving fMRI brain-scans of human subjects. The results show that our proposed method has lower Type I error and higher statistical power compared to alternatives that need to threshold the edge weights. Moreover, they show our proposed method is better suited to deal with highly heterogeneous datasets."
in_NB  to_read  re:network_differences  network_data_analysis  statistics  hypothesis_testing  functional_connectivity  neuroscience  neville.jennifer 
29 days ago
[1808.08811] Exponential inequalities for nonstationary Markov Chains
"Exponential inequalities are main tools in machine learning theory. To prove exponential inequalities for non i.i.d random variables allows to extend many learning techniques to these variables. Indeed, much work has been done both on inequalities and learning theory for time series, in the past 15 years. However, for the non independent case, almost all the results concern stationary time series. This excludes many important applications: for example any series with a periodic behaviour is non-stationary. In this paper, we extend the basic tools of Dedecker and Fan (2015) to nonstationary Markov chains. As an application, we provide a Bernstein-type inequality, and we deduce risk bounds for the prediction of periodic autoregressive processes with an unknown period."
to:NB  to_read  markov_models  mixing  learning_theory 
29 days ago
[0802.0021] Time series analysis via mechanistic models
"The purpose of time series analysis via mechanistic models is to reconcile the known or hypothesized structure of a dynamical system with observations collected over time. We develop a framework for constructing nonlinear mechanistic models and carrying out inference. Our framework permits the consideration of implicit dynamic models, meaning statistical models for stochastic dynamical systems which are specified by a simulation algorithm to generate sample paths. Inference procedures that operate on implicit models are said to have the plug-and-play property. Our work builds on recently developed plug-and-play inference methodology for partially observed Markov models. We introduce a class of implicitly specified Markov chains with stochastic transition rates, and we demonstrate its applicability to open problems in statistical inference for biological systems. As one example, these models are shown to give a fresh perspective on measles transmission dynamics. As a second example, we present a mechanistic analysis of cholera incidence data, involving interaction between two competing strains of the pathogen Vibrio cholerae."
in_NB  statistics  time_series  simulation  to_teach:data_over_space_and_time 
29 days ago
Reply to ‘Sigmoidal Acquisition Curves are Good Indicators of Conformist Transmission’ | Scientific Reports
"In the Smaldino et al. study ‘Sigmoidal Acquisition Curves are Good Indicators of Conformist Transmission’, our original findings regarding the conditional validity of using population-level sigmoidal acquisition curves as means to evidence individual-level conformity are contested. We acknowledge the identification of useful nuances, yet conclude that our original findings remain relevant for the study of conformist learning mechanisms."
to:NB  cultural_transmission  to_read  re:do-institutions-evolve 
29 days ago
Sigmoidal Acquisition Curves Are Good Indicators of Conformist Transmission | Scientific Reports
"The potential for behaviours to spread via cultural transmission has profound implications for our understanding of social dynamics and evolution. Several studies have provided empirical evidence that local traditions can be maintained in animal populations via conformist learning (i.e. copying the majority). A conformist bias can be characterized by a sigmoidal relationship between a behavior’s prevalence in the population and an individual’s propensity to adopt that behavior. For this reason, the presence of conformist learning in a population is often inferred from a sigmoidal acquisition curve in which the overall rate of adoption for the behavior is taken as the dependent variable. However, the validity of sigmoidal acquisition curves as evidence for conformist learning has recently been challenged by models suggesting that such curves can arise via alternative learning rules that do not involve conformity. We review these models, and find that the proposed alternative learning mechanisms either rely on faulty or unrealistic assumptions, or apply only in very specific cases. We therefore recommend that sigmoidal acquisition curves continue to be taken as evidence for conformist learning. Our paper also highlights the importance of understanding the generative processes of a model, rather than only focusing solely on the patterns produced. By studying these processes, our analysis suggests that current practices by empiricists have provided robust evidence for conformist transmission in both humans and non-human animals."
to:NB  cultural_transmission  to_read  re:do-institutions-evolve 
29 days ago
Conformity cannot be identified based on population-level signatures | Scientific Reports
"Conformist transmission, defined as a disproportionate likelihood to copy the majority, is considered a potent mechanism underlying the emergence and stabilization of cultural diversity. However, ambiguity within and across disciplines remains as to how to identify conformist transmission empirically. In most studies, a population level outcome has been taken as the benchmark to evidence conformist transmission: a sigmoidal relation between individuals’ probability to copy the majority and the proportional majority size. Using an individual-based model, we show that, under ecologically plausible conditions, this sigmoidal relation can also be detected without equipping individuals with a conformist bias. Situations in which individuals copy randomly from a fixed subset of demonstrators in the population, or in which they have a preference for one of the possible variants, yield similar sigmoidal patterns as a conformist bias would. Our findings warrant a revisiting of studies that base their conformist transmission conclusions solely on the sigmoidal curve. More generally, our results indicate that population level outcomes interpreted as conformist transmission could potentially be explained by other individual-level strategies, and that more empirical support is needed to prove the existence of an individual-level conformist bias in human and other animals."
to:NB  cultural_transmission  to_read  re:do-institutions-evolve 
29 days ago
The New Mechanical Philosophy - Stuart Glennan - Oxford University Press
"The New Mechanical Philosophy argues for a new image of nature and of science--one that understands both natural and social phenomena to be the product of mechanisms, and that casts the work of science as an effort to discover and understand those mechanisms. Drawing on an expanding literature on mechanisms in physical, life, and social sciences, Stuart Glennan offers an account of the nature of mechanisms and of the models used to represent them. A key quality of mechanisms is that they are particulars - located at different places and times, with no one just like another. The crux of the scientist's challenge is to balance the complexity and particularity of mechanisms with our need for representations of them that are abstract and general.
"This volume weaves together metaphysical and methodological questions about mechanisms. Metaphysically, it explores the implications of the mechanistic framework for our understanding of classical philosophical questions about the nature of objects, properties, processes, events, causal relations, natural kinds and laws of nature. Methodologically, the book explores how scientists build models to represent and understand phenomena and the mechanisms responsible for them. Using this account of representation, Glennan offers a scheme for characterizing the enormous diversity of things that scientists call mechanisms, and explores the scope and limits of mechanistic explanation."
to:NB  books:noted  philosophy_of_science  explanation_by_mechanisms  via:rvenkat 
4 weeks ago
Under Contract: The Invisible Workers of America's Global War | Noah Coburn
"War is one of the most lucrative job markets for an increasingly global workforce. Most of the work on American bases, everything from manning guard towers to cleaning the latrines to more technical engineering and accounting jobs, has been outsourced to private firms that then contract out individual jobs, often to the lowest bidder. An "American" base in Afghanistan or Iraq will be staffed with workers from places like Sri Lanka, Bangladesh, the Philippines, Turkey, Bosnia, and Nepal: so-called "third-country nationals." Tens of thousands of these workers are now fixtures on American bases. Yet, in the plethora of records kept by the U.S. government, they are unseen and uncounted—their stories untold.
"Noah Coburn traces this unseen workforce across seven countries, following the workers' often zigzagging journey to war. He confronts the varied conditions third-country nationals encounter, ranging from near slavery to more mundane forms of exploitation. Visiting a British Imperial training camp in Nepal, U.S. bases in Afghanistan, a café in Tbilisi, offices in Ankara, and human traffickers in Delhi, Coburn seeks out a better understanding of the people who make up this unseen workforce, sharing powerful stories of hope and struggle.
"Part memoir, part travelogue, and part retelling of the war in Afghanistan through the eyes of workers, Under Contract unspools a complex global web of how modern wars are fought and supported, narrating war stories unlike any other. Coburn's experience forces readers to reckon with the moral questions of a hidden global war-force and the costs being shouldered by foreign nationals in our name."
to:NB  books:noted  us_military  american_hegemony  the_continuing_crises  us-afghan_war 
4 weeks ago
Hello World | W. W. Norton & Company
"If you were accused of a crime, who would you rather decide your sentence—a mathematically consistent algorithm incapable of empathy or a compassionate human judge prone to bias and error? What if you want to buy a driverless car and must choose between one programmed to save as many lives as possible and another that prioritizes the lives of its own passengers? And would you agree to share your family’s full medical history if you were told that it would help researchers find a cure for cancer?
"These are just some of the dilemmas that we are beginning to face as we approach the age of the algorithm, when it feels as if the machines reign supreme. Already, these lines of code are telling us what to watch, where to go, whom to date, and even whom to send to jail. But as we rely on algorithms to automate big, important decisions—in crime, justice, healthcare, transportation, and money—they raise questions about what we want our world to look like. What matters most: Helping doctors with diagnosis or preserving privacy? Protecting victims of crime or preventing innocent people being falsely accused?
"Hello World takes us on a tour through the good, the bad, and the downright ugly of the algorithms that surround us on a daily basis. Mathematician Hannah Fry reveals their inner workings, showing us how algorithms are written and implemented, and demonstrates the ways in which human bias can literally be written into the code. By weaving in relatable, real world stories with accessible explanations of the underlying mathematics that power algorithms, Hello World helps us to determine their power, expose their limitations, and examine whether they really are improvement on the human systems they replace."
to:NB  books:noted  data_mining  machine_learning  prediction 
4 weeks ago
Weighted Sums of Random Kitchen Sinks: Replacing minimization with randomization in learning
"Randomized neural networks are immortalized in this AI Koan: In the days when Sussman was a novice, Minsky once came to him as he sat hacking at the PDP-6. What are you doing?'' asked Minsky. I am training a randomly wired neural net to play tic-tac-toe,'' Sussman replied. Why is the net wired randomly?'' asked Minsky. Sussman replied, I do not want it to have any preconceptions of how to play.'' Minsky then shut his eyes. Why do you close your eyes?'' Sussman asked his teacher. So that the room will be empty,'' replied Minsky. At that moment, Sussman was enlightened. We analyze shallow random networks with the help of concentration of measure inequalities. Specifically, we consider architectures that compute a weighted sum of their inputs after passing them through a bank of arbitrary randomized nonlinearities. We identify conditions under which these networks exhibit good classification performance, and bound their test error in terms of the size of the dataset and the number of random nonlinearities."

--- Have I never bookmarked this before?
in_NB  approximation  kernel_methods  random_projections  statistics  prediction  classifiers  rahimi.ali  recht.benjamin  machine_learning  have_read 
5 weeks ago
[1712.05630] Sparse principal component analysis via random projections
"We introduce a new method for sparse principal component analysis, based on the aggregation of eigenvector information from carefully-selected random projections of the sample covariance matrix. Unlike most alternative approaches, our algorithm is non-iterative, so is not vulnerable to a bad choice of initialisation. Our theory provides great detail on the statistical and computational trade-off in our procedure, revealing a subtle interplay between the effective sample size and the number of random projections that are required to achieve the minimax optimal rate. Numerical studies provide further insight into the procedure and confirm its highly competitive finite-sample performance."
to:NB  principal_components  sparsity  random_projections  statistics  samworth.richard_j. 
5 weeks ago
[1801.03896] Robust inference with knockoffs
"We consider the variable selection problem, which seeks to identify important variables influencing a response Y out of many candidate features X1,…,Xp. We wish to do so while offering finite-sample guarantees about the fraction of false positives - selected variables Xj that in fact have no effect on Y after the other features are known. When the number of features p is large (perhaps even larger than the sample size n), and we have no prior knowledge regarding the type of dependence between Y and X, the model-X knockoffs framework nonetheless allows us to select a model with a guaranteed bound on the false discovery rate, as long as the distribution of the feature vector X=(X1,…,Xp) is exactly known. This model selection procedure operates by constructing "knockoff copies'" of each of the p features, which are then used as a control group to ensure that the model selection algorithm is not choosing too many irrelevant features. In this work, we study the practical setting where the distribution of X could only be estimated, rather than known exactly, and the knockoff copies of the Xj's are therefore constructed somewhat incorrectly. Our results, which are free of any modeling assumption whatsoever, show that the resulting model selection procedure incurs an inflation of the false discovery rate that is proportional to our errors in estimating the distribution of each feature Xj conditional on the remaining features {Xk:k≠j}. The model-X knockoff framework is therefore robust to errors in the underlying assumptions on the distribution of X, making it an effective method for many practical applications, such as genome-wide association studies, where the underlying distribution on the features X1,…,Xp is estimated accurately but not known exactly."
to:NB  regression  variable_selection  statistics  samworth.richard_j.  knockoffs  to_teach:linear_models 
5 weeks ago
[1711.06642] Nonparametric independence testing via mutual information
"We propose a test of independence of two multivariate random vectors, given a sample from the underlying population. Our approach, which we call MINT, is based on the estimation of mutual information, whose decomposition into joint and marginal entropies facilitates the use of recently-developed efficient entropy estimators derived from nearest neighbour distances. The proposed critical values, which may be obtained from simulation (in the case where one marginal is known) or resampling, guarantee that the test has nominal size, and we provide local power analyses, uniformly over classes of densities whose mutual information satisfies a lower bound. Our ideas may be extended to provide a new goodness-of-fit tests of normal linear models based on assessing the independence of our vector of covariates and an appropriately-defined notion of an error vector. The theory is supported by numerical studies on both simulated and real data."
in_NB  heard_the_talk  dependence_measures  hypothesis_testing  nonparametrics  nearest-neighbors  statistics  samworth.richard_j. 
5 weeks ago
[1606.00304] Efficient multivariate entropy estimation via $k$-nearest neighbour distances
"Many statistical procedures, including goodness-of-fit tests and methods for independent component analysis, rely critically on the estimation of the entropy of a distribution. In this paper, we seek entropy estimators that are efficient and achieve the local asymptotic minimax lower bound with respect to squared error loss. To this end, we study weighted averages of the estimators originally proposed by Kozachenko and Leonenko (1987), based on the k-nearest neighbour distances of a sample of n independent and identically distributed random vectors in ℝd. A careful choice of weights enables us to obtain an efficient estimator in arbitrary dimensions, given sufficient smoothness, while the original unweighted estimator is typically only efficient when d≤3. In addition to the new estimator proposed and theoretical understanding provided, our results facilitate the construction of asymptotically valid confidence intervals for the entropy of asymptotically minimal width."
in_NB  heard_the_talk  entropy_estimation  statistics  nearest-neighors  samworth.richard_j. 
5 weeks ago
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