Business Intelligence Tips

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.”

Seven Principles For Effective Visual Presentations In Performance Reporting - #4: Visual Properties That Represent Values Should Accurately Correspond To The Actual Differences They Represent.

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 fourth of these is presented below:
“Graphs are sometimes intentionally designed to deceive, to misrepresent the truth by visually encoding values in a way that does not correspond to the actual values themselves and the differences between them. Even more often, however, people unintentionally misrepresent data in this manner, simply because they don't understand this principle and how to follow it. The most common way that this occurs involves bar graphs with quantitative scales that don't begin at zero. Because the lengths of bars encode the values they represent, the full length of the bar must be displayed, beginning from zero, for the values to be encoded properly." Few refers to a graph and says "notice that actual sales in the East region appear to be twice as great as planned sales, but in fact, this is far from the truth. Actual sales are only 5 percent greater than the plan. When you use a graph to communicate, people should be able to look at the graphical representation alone to compare differences in values. If the graph doesn't support this operation, what's the point of using a graph?”

Seven Principles For Effective Visual Presentations In Performance Reporting - #3: Use Lengths Or Other Dimensional Technique To Further Encode Quantitative Values In Graphs.

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 third of these is presented below:
“There is an important set of visual properties that are called “preattentive attributes” of visual perception. They are preattentive in that the process of perceiving them does not involve conscious thought; it is automatic and immediate. This includes such properties as an object's length (for example, the length of bar in a bar graph), its 2-D location (for example, the position of a data point in a scatterplot), its size, its shape, its orientation, its hue, and so on. If objects in a graph vary from one another along one of these properties to a great enough degree to appear different, we see those differences immediately, without conscious effort. For example, if a single data point is orange in a scatterplot that contains 100 data points, 99 of which are black, the orange dot will stand out as different. We can use this knowledge to intentionally make particular items in a graph stand out as different or important.”

“Of the full set of preattentive attributes, a few are perceived quantitatively. By this I mean that we perceive differences between varying expressions of a visual property (for example, length, exhibited as long bars, short bars, medium-length bars, etc.) as greater than or less than one another. Apart from these preattentive attributes, those that are not perceived quantitatively are simply seen as different, such as the different hues of black, green, blue, orange, purple, and so on. Two of the preattentive attributes that are perceived quantitatively are also perceived with a fair amount of quantitative precision: length and 2-D position.”

Seven Principles For Effective Visual Presentations In Performance Reporting - #2: Avoid Displaying Meaningless Differences.

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 second of these is presented below:
“Because differences in visual properties, such as color, are used to communicate actual differences in the information itself, visual differences should never be used arbitrarily. When people notice visual differences, they try to discern the meaning of those differences. Don't confuse people and waste their time by including visual differences that are meaningless. Figure 5 shows a common example of how this rule is broken. What is the meaning of the different colors that appear on the bars? The answer is “nothing.” We already know what the bars represent, because they are labeled as years along the X-axis. Meaningless visual differences such as this gratuitous use of color not only cause people to search for meanings that don't exist, but in this case they clutter the graph with an eye-assaulting abundance of color.”

Seven Principles For Effective Visual Presentations In Performance Reporting - #1: Display Only That Which Is Relevant.

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 first of these is presented below:
“When you wish to get your message across—any message—whether in conversation, in writing, or in a graph, irrelevant content is distracting. Don't make people wade through meaningless visual content in your display to find what really matters. It has become common today, even in business graphs, to include all sorts of nonsense, such as cute pictures in the background or the addition of a third dimension to bars, lines, and pies. Despite good intentions (if you consider attempts to entertain or impress good), visual content of this sort is something that people's eyes must scan and brains must process, without any payback, for it is meaningless.”

“Extraneous content not only wastes people's time, it makes it harder for them to get at the message.
The reverse is true as well. Don't design a display that doesn't contain everything people need to make sense of it. Include every piece of information that is part of your message—even notes to explain what might not be clear—otherwise you're communicating poorly. This principle is broken in many graphs today by adding a 3-D effect to bars, lines, data points, and pies.”