Viewing a slide only if another slide hasn't already been viewed
Looking for suggestions on how to do the following:
1. I have a lesson with multiple scenes. Two of them cover how to respond to certain events in different ways depending on whether the event is or is not safety critical.
2. I have a single slide that is relevant regardless of which scene they view.
3. I placed the slide at the end of both scenes, but I only want it to be displayed if they haven't already viewed it in the other scene. Learners will view both scenes but night do it in any sequence and I don't want them to have to view the slide again at the end of scene 4 if they already saw it at the end of scene 3 and vice versa.
A colleague suggested creating T/F variables that are False until the slide is viewed and then True. And then creating a trigger that says to play slide 3.5 only if slide 4.5 is False, otherwise skip slide 3.5.
But I'd like them to be able to return to slide 3.5 (or 4.5) later if necessary, and once they've both been set to True they wouldn't be able to launch either one because the trigger would cause the slide to be skipped.
Any ideas on how to do this?