Off the top of my head, I think it's a few things: * Neutral/textbook-like personality * Lack of first-person pronouns * Lack of any indication of relevant e

Off the top of my head, I think it's a few things: * Neutral/textbook-like personality * Lack of first-person pronouns * Lack of any indication of relevant experience/credentials * Lack of any tangents, stories, or any other attempt to relate with the reader * High confidence/authoritativeness/matter-of-factness * Lack of external sources or URLs * Lack of any deep connection to the context of the conversation (such as a tie-in to other aspects of the thread, a reference to some aspect of HN, a reference to current events / pop culture, etc.) * At least in this case, an overly literal interpretation of the question (despite being phrased as such, most humans wouldn't have interpreted reactspa's comment as a yes-or-no question) Overall, it's not bad at answering questions, but the fact that it doesn't attempt to impersonate humans by default can give its output a bit of an uncanny valley feeling.