"Unless the behaviours and personalities of these things that compute are designed well enough the things that are not so good about them or unavoidable have the potential to come across as flaws in the object’s character, break the suspension of disbelief and do more harm than good. Running out of batteries, needing a part to be replaced or the system crashing could be seen as getting sick, dying - or worse - the whole thing could be so ridiculous and annoying that it gets thrown out on its ear before long." Lots of cracking stuff in this: designing personas, making personalities that aren't annoying, persona-design as role-playing or improv.