The spotting routine surfaces thinking hotspots around truth that otherwise we wouldn’t see. It raises our awareness of these hotspots for other situations too. The process is self-documenting through the chart.
Note that there are many reasons why an idea can be uncertain. Importance is also a complex judgment -- an idea can be important simply because it's fascinating, or because it's important to understanding the way the world works, or because it has great practical implications. The point about reasons for uncertainty and importance in the spotting hotspots routine is not to judge them but to make them more visible, expanding students' consciousness of them.
Naturally, older students will have more sophisticated ideas and younger students less sophisticated ones in trend. This is fine. Again, the goal is not to push students hard toward greater sophistication but to make visible what they already know, encouraging them to be more alert to problems of truth and think about them more actively.
You can ask students to do the routine by themselves in small groups. When the class is large and students have many ideas, small groups may work better. Also, when the group is large, to save time you can have each student write an idea on a post-It and stick it up on the chart, and then discuss some of them.Or you can have the students think in small groups, with each group nominating one idea to put up on the chart.
Not only groups but individuals can do hotspot spotting, for instance as part of an assignment.
Finally, students may say, “That’s important but we can’t really find out information about it!” You can acknowledge that and say, well, then we just have to keep it in mind for the future. Or you might say, “Suppose we had all the resources we needed, what could we do to investigate it?”