What is data visualization?
Although the general concept of data visualization is straightforward, let's take some time to set the scene properly. The essential objective of data visualization is to transfer a message made of data to another human being. Being effective at this communication process implies that the receiver comprehends the original data-based message and "makes sense" of it through cognition. Figure 7.1 shows a graphical representation of a bad attempt of communicating data messages: presenting it all in its original format:
Figure 7.1: Presenting data in its original format: as you can see, the decision-maker is visibly overwhelmed, and the large majority of the data is ignored
The decision-maker here is clearly overwhelmed by such a large amount of raw data being offered. This is understandable: every human being has a limited amount of cognitive capacity, and our brains can only process a certain quantity of information at once. If we try...