It's now time to focus on the next part of this module. At the beginning I said that we will look first at single view methods, and then multiple linked view methods. Now, it's time to talk about multiple views methods. What is the main idea here? Well, the idea is that, in a visualization system or application, we can in principle use multiple views to visualize data at the same time with different views. So, all the methods that I have introduced so far are interactive methods that work with only one single view, but there's no reason why we shouldn't be able to use them with multiple views. An interesting idea of multiple views is that these views can be used not only to visualize different aspects of the same data, but also to make sure that when you interact with one view, the interaction is actually reflected in the other view. As we will see soon, this is a very powerful method in visualization. So, for the rest of the course, I'm going to focus exclusively on the situation where there are only two views and this is for simplicity. But there's no reason why this shouldn't be extended to multiple views. So, again, I'm going to talk only about cases of two views, but it's very easily generalizable to situations where you have N views. Okay? So, before we go into the specific methods and techniques that can be used, I want to briefly discuss why use multiple linked views at all. What are the advantages of using multiple views? Well, I think there are two main reasons why we may want to use multiple views. The first one is that, it's not always possible to visualize all the information that you want to extract from a given dataset in one single view. A typical example is datasets that contain information about, say the geography of somethings, spatial information, and temporal information. Now, even though there are methods that can integrate in one single view: time and space at the same time, it's evident that there are situations out there where it may be useful to actually rather than integrate everything in one single view, at one view that depicts the temporal aspects of the data, and one view that represents the spatial aspects of the data, and then link them together in a way that when I interact with time, I can see the effect on space and the other way around. That's just an example, it's not always about space and time. It can be about a lot of different aspects. But the basic idea is that, from a given dataset we can extract different types of information, and these different types of information, you may want to arrange these different types of information in different views. Another aspect is more related to interaction. The idea here is that, once we have two views, what is very useful to do is to be able to select or interact with elements of one view and have these action affect the other view. There are at least three main types of connections that you may want to have there. One is navigation. So, as I navigate information in one view, I can see the details of these navigation in the other view. Another situation is, when I select some elements in one view, I want to see the same elements selected in the other view. The last one is, if I filter the elements in one view, using for instance the dynamic queries method that I've shown you in the previous video, then I want these filtering to be reflected in the other view. So, this is a general overview of what we can do with multiple linked views and why. In the next videos, I'm going to show you specific methods and different ways we can create multiple views and we can link them together.
