I just have one more comment on tactical tutorials. They have one more significant application beyond performance support systems. We have designed CBT applications that are entirely based on problem scenarios. The user works through the problem, receiving no instruction until he/she asks for it or does something indicating a need for instruction. Then we provide one of the brief tutorials (perhaps as brief as one window of text describing how to do whatever is needed right now).
The largest such application was one for a pharmacy system. We learned in the front end analysis that most of the population had some experience with pharmacy management software, but none with this system. Since this system was very consistent in its operation, and all such systems do the same things, we adopted the problem scenario strategy, with tactical tutorials. The result was huge time savings in instruction, since we could capitalize on whatever the user already knew.
What makes this strategy conceptually difficult in the framework is this: Some of the interaction occurs outside of the tutorial (in the problem scenario or the application itself) and is not even part of the tutorial unless something happens (an error or user request) that makes it a part of the tutorial rather than the surrounding application. So the context and structure (prompt, response type, etc.) may be beyond the control of the tutorial and the designer. Makes it interesting.