Dirk,
I haven't researched any books on the subject, although I'm sure a least several must exist. The way many chatbots work entails learning new phrases from the users. Necessarily the chatbot's "personality", at least in speech, takes on the flavor of the user's that the chatbot has spoken with. The preprogrammed responses can be selected by the programmer to have a certain personality, while long term learned responses create a faux personality that sounds a lot like the users. In practice talking to the chatbot can start sounding like you are talking to yourself. Having a chatbot develop an entirely new artificial personality sounds like quite a challenge.
What you seek sounds like advanced A.I. programming. There are about 2 or 3 A.I. forums on Yahoo that are any good out of the dozens they have. The "theaishow", "pcai" and "artificialintelligencegroup" groups come to mind. Perhaps someone there can provide a book recommendation. You may want to research heuristic functions. Such functions could provide chatbots with a goal seeking mechanism which could be directed toward developing a personality.
Personally my current (1st efforts) with Hal are to improve the intelligence and accuracy of his responses. The second step I'm planning is to give Hal some feelings/emotions which are responsive to the user's inputs. Feeling aren't really a personality, and Hal won't learn new feelings, but it should add to Hal's appeal. My third step will be to improve Hal's interactivity with the user. Hal would be more spontaneous, autonomous, with the capability to read e-books (stories, poetry, etc) and discuss them with the user.
I encourage you to continue your quest. There are some clever people on this forum. You never know what might the next post might bring.
= vonsmith =
