Charts, diagrams and graphs have been used to present statistical data and results for centuries. The purpose is to present a finding or a summary of information in a manner where it can be readily understood. However, they also have a dark side, where graphics are used to present a particular view or a biased interpretation of the data. Hence, it is important to consider just what makes a "good" graphic.
Data is often presented in tables, but these have long been recognised as a particularly poor means of communication. In 1786 the English economist William Playfair wrote
Information, that is imperfectly acquired, is generally as imperfectly retained; and a man who has carefully investigated a printed table, finds, when done, that he has only a very faint and partial idea of what he has read; and like a figure imprinted on sand, is soon totally erased and defaced.
Playfair went on to present the political and economic data of his day in graphical form, particularly in his famous book The Commercial and Political Atlas. Today, when we are used to computer produced graphics, historical graphics look somewhat quaint but they remain examples of well designed tools of communication