This third problem, the presentation problem, occurs when your visualization is too large to be displayed on the screen you are using in your application. And this happens very frequently when you have a large dataset. So, you have decided how to map your dataset into a visualization, but your visualization is too large to fit the screen. And then you have to use some presentation techniques, for example the fish-eye view. With a fish-eye view, the data in the centre of the screen are magnified, while the data towards the periphery of the screen are compressed. In such a way, you are able to fit all the visualization on a single screen, the user is able to focus on the interesting data, on the data which are of interest in that moment, but the context is not lost.