Great, read, Tina!
Part of the confusion out there is about the actual definition of interactivity. People tend to mix two types of interactivity: user interface (physical between your mouse and the application) and learning (mental process, decision making, feedback loop). The latter, you do it every day when you work. Without any courses. Like reading this post. You decided to read Trina's words. It does not involve too much, maybe scrolling. But the meaning behind the words resonates, you decide to try something new next time. You get feedback on how it went. That's important mental interactivity.
On the other hand, for example, here's my pet peeve the "click to reveal" concept. That is physical interaction between you and the object to click on to reveal the text behind. Unless it also comes with a question maybe, or decision, it is strictly a click. AN EXTRA CLICK just to see something!
Don't get me wrong, there are appropriate ways to use click to reveal but if the learner's goal is to find info quickly, it is just a noise in the system. It also makes me suspicious. If it is relevant and important, why is it hiding? What if I missed clicking on that thing? Oh, that's why I can't move on from this page, it forces me to click. Got it. So, now my mind is totally somewhere else...