A colleague at our uni is using WeBWorK for the first time, and is very interested in duplicating a style of question he uses in his first-year physics classes that they've called "integrated testlets". They're basically IFCAT if you know what that is: answer-until-correct setup, where students are given expanded feedback and detail, at the expense of less points. So a student answers part (a), gets it wrong, gets more details, answers (b) which is an expanded (a), gets it right, and gets 70% on that question (with variations).
The Just-In-Time seems very close to this, and he's been playing around with it, but there's one problem that doesn't quite make it work. If you have a parent to a JIT question chain, and you get it wrong / the child spawns, students can still change their answers in the parent and continue Check Answer-ing until they get the correct response. It doesn't update the parent grade, but it does give them the correct response which they can then use in the child.
So, the question is: any thoughts on how to avoid this? Is it possible to remove the clickability / presence of the Check Answers button entirely until some point (e.g., after the deadline for the assignment)? Otherwise, the propagating nature of a testlet means the answer to (a) is the same as the answer to (b), and it's just sitting there waiting for the students to click repeatedly until they get it correct.
Any thoughts are welcome, especially those that don't require that I hack at the JIT Perl. :)