'We're more reluctant to offer cues as to how the audience is supposed to react in different situations, which confuses certain people. It's not a question of not being willing to follow -- Joel Coen
Available Now: Playwriting Seminars 2.0
The revised and expanded e-book edition.
Here's the full Table of Contents and ordering link for the new edition.
Following is one of the 10 new diagrams in the new edition to help explain concepts of dramatic writing.

http://www.vcu.edu/arts/playwriting/