When something is selected in a visualization, we saw previously, that one reaction is to highlight the elements that are selected. Now, that's not the only possible reaction, there are other possible reactions that can happen at the same time. So, the first one is to show more information, and a clear example of that, is what we have seen in the previous videos. So, when I go over the dots of the scatter plots, there is more information that is coming up from the visualization. Another example that we will see later on, is with multiple views, when I select some elements on the screen, I can have another view reflecting the information, giving me more information about the elements that I've just selected. So, in general, another important reaction of selection is showing more information about the elements that I've just selected. Finally, another possible reaction to selection, is to apply an operation to the elements that have been selected. So, here there is another one of those situations where the possibilities are endless. I'm just going to mention some common operations that are applied to selected elements in interactive visualization systems, but this is by no means an exhaustive list, it's just examples of some common operations that are applied to selected elements. The first one is to delete or forget the elements. It is possible, that for some reason, you want to eliminate from your visualization some elements, typically, when you have some outliers, you may want to remove these outliers, re-scale the visualization and see what happens. Another one is to focus on something. So, you select some elements, and you ask the system to focus only on those elements. Another one is to save or label these elements, so that I can remember that this group, is for some reason, important for me in the analysis. So, with this last one, we cover all the possible reactions that we have to a selection. So, recapitulating, we have highlighting, then we have showing additional information, and finally, we have apply some operation to the selected elements.