This is the title of a post by Kate Goldfield on her aspiefrommaine blog http://www.freewebs.com/aspiefrommaine/mybaltimoresunarticle.htm
In it she talks about how AS people have trouble knowing what to say in conversations, when to start speaking and when to stop speaking.
In her book A different childhood Iris Johansson describes how she handled this problem by memorizing conversation starters and conversation enders as well as the structure of social conversations:
…She also practiced conversation starters. A good starter is: “Where are you off to?” or “Do you want come along …?” or “What do we do now?” or “How do you like …?”
…The problem was what if she got a return question. She learned to duck such questions by starting to tell about something, anything whatever. She had also figured out exactly how long she could talk before it started to bore the other one. She used to ask if the person was in a hurry because then she had to shorten her story.
When the other person in turn began to tell her about something Iris didn’t understand a thing. Everything in her thoughtless talk was without substance to Iris with no fixed points to focus on. Then she would wait until she heard a word that meant something to her. Then, when the other stopped talking Iris posed a question about that word: “You said something about…
…People loved to flaunt their knowledge and a good starter was to say: “Do you know anything about …” In this manner she could milk the other person for talk. Some people didn’t fall for it but on some others it worked very well. She started to seek out people she could talk with this way. She gathered up everything she learned and combined it with the old stuff she knew and created images and films in her head that she could call up when needed.
If the other kept talking too long, it got awkward and then Iris used one of her pre-learned enders: “It was nice to see you” or “Apropos of nothing …” or “By the way I have to …”. That way she could put an end to it.
It helped Iris that she has a practically a photographic memory, so she was always able to retrieve the information needed for the particular situation at hand.