Your play is ready for its first public reading, and afterward, there's going to be a talkback. The mere word often strikes fear in the hearts of playwrights, as a badly managed talkback can be useless or, at its worst, damaging to the play and the playwright. Five simple suggestions to make it more useful:
1. Have someone other than the playwright lead the discussion. Ideally, the moderator should be the director or dramaturg (a sort of advocate for the script who works with the author), or a teacher in a classroom situation. This way, the playwright can focus on listening. On that note...
2. Silent author. The playwright's job is to listen. I write down everything that is said in a discussion, and then later, I'll decide what comments are useful and how to act upon them. If someone in the audience didn't understand something, it's not important that I explain it to them after the fact. What's important is that they didn't understand it. It's up to me to decide what to do about that, or if I need to do anything at all. When moderating, however, I will allow the author to ask questions of the audience at the end. For example, "The peach tree at the end of the play was supposed to represent his mother--did you get that?"
3. Begin the discussion by asking audience members what they liked (aka what worked well for them or what they found most compelling). It's always good to get things going in a positive direction. Personally, I find readings more nerve-wracking than productions, so it helps to start off on a warm and fuzzy note. You can then move on to asking what people didn't understand or had trouble with. Then, one can move on to moments the audience didn't understand or that worked less well for them.
4. It is no one's job to rewrite the play for the playwright. When moderating, immediately cut off someone who says "You should..." That's about the play they would write or the play they wanted to see, not the one the author is working on.
5. Be aware, both as moderator and playwright, that often comments need to be "interpreted." For example, I may tell you that "the betrayal on page 25 was confusing to me." Do not assume that the problem is actually on page 25. It may be, but often, what takes place on page 25 is supposed to be set up on page 15. So it's necessary to look at how you got to the moment being commented on, and see if the path is properly constructed.
Following these suggestions should allow you to have a kinder, gentler and more useful play reading experience. Have fun!