Every analysis, whether on small or large datasets, involves a descriptive statistics step, where the data is summarized and described by statistics such as mean, median, percentages, and correlation. This step is commonly the first step in the analysis workflow, allowing a preliminary understanding of the data and its general patterns and behaviors, providing grounds for the analyst to formulate hypotheses, and directing the next steps in the analysis. Graphs are powerful tools to aid in this step, enabling the analyst to visualize the data, create new views and concepts, and communicate them to a larger audience.
There is a vast amount of literature on statistics about visualizing information. The classic book, Envisioning Information, by Edward Tufte, demonstrates beautiful and useful examples of how to present information in graphical form. In another book, The Visual Display of Quantitative Information, Tufte enumerates a few qualities that a graph...