This has resulted in the use of graphic evidence with extremely high production values. Pictures replace words, icons are used liberally, and color is employed in ways that are seen as psychologically redemptive. It has also resulted in graphics that can be highly deceptive. In part, this may be the eagerness of counsel to communicate a particular point in a particular way. In part, it may be because neither counsel nor the artist in their eagerness to create a pretty picture is aware of how the information is being distorted.

If graphic evidence plays such an important role in the trying of a case and the persuasion of a jury, why do attorneys object so little to the use of particular pieces of demonstrative evidence by opposing counsel? Clearly, one reason is that the attorney is afraid that by raising objections he/she may be opening a can of worms. However, in many instances, the attorney either does not even consider objecting or is not equipped to perceive that there may be grounds for objecting.

In some instances, the deception is obvious enough that opposing counsel can easily see it and mount an effective objection.

In other instances, the deception is more subtle. In this article, we set out to give examples of ways in which graphic evidence may be subtly deceptive. By being aware of this deception, opposing counsel can either make an argument that points out to the court how the exhibit¹s probative value is outweighed by its prejudicial impact, or alternatively, produce a counter exhibit.

Edward R. Tufte in his book, The Visual Display of Quantitative Information, developed a measurement he called the lie factor. It is used to measure violations of the principle that "the representation of numbers, as physically measured on the surface of the graphic itself, should be directly proportional to the numerical quantities represented." It is measured as follows:

A graphic that has a lie factor of 1 can generally be assumed to be truly reflecting the underlying data. The higher the lie factor the more deceptive the graphic is. Here are some examples, based on Tufte¹s book, and adapted to a litigation context. The charts depicted show the same information. From 1986 to 1988, the plaintiff¹s income increased by 80%. However, the graphical distortion in the chart to the right makes this increase look a great deal larger. Using Tufte¹s formula, we find it has a lie factor of 3.7, far outside the range of what is acceptable. The chart below has a lie factor of 1 and so can be seen as reasonably reflecting the data.

Use Of Irregular Scales and Design Changes

Tufte writes that "Each part of a graphic generates visual expectations about its other part and, in the economy of graphical perception, these expectations often determine what the eye sees. Deception results from the incorrect extrapolation of visual expectations generated at one place on the graphic to other places." Many graphics used in the courtroom utilize scales which may show, for instance, the passage of time, amounts of money, levels of some substance, and so on. Attorneys should be on the lookout for changes or disruptions in the scale that can deceive the juror into perceiving a pattern that does not exist.

The graphic to the left, for example, uses area to display one-dimensional data. The increase in the average cost per day of worker¹s compensation from 1975 to 1990 is 130%. But the 1990 figure is obviously more than 1.3 times as large as the figure in 1975. Similarly, the horizontal line for 1990 is about 5 1/2 times the length of the line for 1975.

Whenever graphic evidence uses a picture to represent a number, the attorney should be particularly suspicious. Often there may be a change in the "volume" (3 dimensions) of the picture meant to demonstrate a change in one dimension, but instead, resulting in terrible distortion. Generally, less extreme, but still possible distorting is the representation of one-dimensional data by two-dimensional drawings.

The exhibit to the right illustrates this problem. Data show that adverse reactions to a drug are one in ten thousand. By illustrating this using "volume" or 3 dimensions in this chart, the "adverse reaction" takes on an alarming and inaccurate size. It deceives the jury into believing the drug to be far more dangerous than warranted. The defense might redesign this chart and make its point more powerfully and honestly like the chart below.

Tufte writes that, "The number of information-carrying (variable) dimensions depicted should not exceed the number of dimensions in the data."

Shape of Graphics

Tall thin graphics make increases and decreases in data appear extreme. Short wide graphics make changes in data appear to be slight.

If we examine the chart to the left, we see that by intentionally making this graph tall and thin, it appears that HDC is out-performing IBM common stock by an extremely wide margin as of 1988. The chart below is perhaps a more reasonable representation of the stocks¹ comparative returns.

While an attorney could probably not successfully object to a chart for the manipulative nature of its dimensions (although one should not assume lack of success), it may pay to produce an alternative version of the same data that presents them in a more realistic light.

Use Of Nominal Units in Display of Money

Too often graphic evidence that shows changes in amounts of money over time do not take into account changes in the value of money. Dollars do not buy the same amount of goods and services at different points in time. Graphic evidence that fails to use deflated, inflated or standardized units of money are clearly deceptive and therefore prejudicial. The chart to the right illustrates the rising cost of crude oil from 1970 to 1979. Compare this chart to the one below where the cost has been adjusted for inflation of real spending per capita. Two very different pictures emerge.

Conclusion Graphic evidence is important and can have an enormous impact on juror decision-making. We have found that in some cases a particular piece of graphic evidence was instrumental in persuading a jury. However, we find all too often the use of graphic evidence that is extremely beautiful, well designed, and deceptive. Attorneys should become more responsible for both policing the graphic evidence that they have produced for their own case as well as that produced for their opponents¹ case. Do not make the exhibit exchange date a pro forma event, but carefully scrutinize what you are given and object vociferously to those that lack "graphical integrity".