Seven Principles For Effective Visual Presentations In Performance Reporting - #5: Avoid Visual Connection Of Discrete Values Thus Creating False Relationships In The Data.

Stephen Few, a respected IT innovator, consultant, and educator has studied the art and science of visual presentation for many years. In a White Paper prepared for Cognos Corporation, he presents seven principles for the effective display of quantitative information. The fifth of these is presented below: “Values that we display in graphs are sometimes intimately related to one another and sometimes they are discrete. The way we visually display these values should make it easy to see, without effort, this distinction. […In such a] graph, lines connect values, suggesting a relationship between them that doesn’t exist. [...Likewise, depicting data, such as geographic] regions North, East, South, and West are discrete, so values that measure something going on in these regions should be displayed as discrete. Connecting them with a line is misleading. Doing so forms a pattern of upwards and downwards slopes that are utterly meaningless.”