Jury Selection

Use FactLogic to select the most favorable jurors.

Definitions

Voir Dire. Voir dire is the process in which the judge and/or the attorneys examine prospective jurors to determine their suitability. Following are some general notes about voir dire.

Examination of Potential Jurors. Voir dire can be conducted by various parties:

judge only (most federal courts and 20 states),
judge and lawyers (some federal courts and 22 states), and
lawyers only (8 states).

Anonymous voir dires are conducted in some highly publicized cases.

Rejection of Potential Jurors. Systematic rejection is forbidden. A potential juror may be rejected if the judge or the magistrate accepts a challenge. The challenge may be with a stated cause or without a stated cause (called a peremptory challenge). The number of peremptory challenges allowed by each party is set by statute or court rule. The number of peremptory challenges for each party in federal cases depends upon

whether the case is civil or criminal,
the number of alternates,
the penalty, and
the number of defendants and plaintiffs.

Focus Group. A focus group is a number of persons whose judgments are sought to emulate the judgments of a subsequent "real" group (i.e., target group).

Internet Focus Group. An Internet focus group registers its judgments interactively over the Internet. The Decision Channel maintains a list of registered users, together with their demographic information. They are experienced with FactLogic and its use on the Internet, and they have expressed willingness to participate in focus groups for a modest fee.

Because potential jurors can be challenged, jurors needn't be selected randomly from a venire. It is known that the way jurors view evidence depends upon their demographic characteristics. To know which jurors are least/most favorable to the evidence in your case, do the following:

Select a focus group.
Let each member of the focus group judge the evidence and provide his/her idea of the standard of proof (for a criminal case). The following difference is called the margin. It is determined by FactLogic for each member of the focus group:
Margin = (Probability of Responsibility) - (Standard of Proof).¹

The margin is the decision by each member of the focus group, and only FactLogic can measure it.
Conduct an experiment to predict verdicts from the response variables from different subgroups. Subgroups are selected from the focus group according to different values of demographic characteristics. Only FactLogic can predict verdicts from the quantified judgments from the members of a focus group.
Select jurors based upon the result of the experiment.

1. Select a Focus Group

To select a jury, first select a focus group so that an experiment might reveal which demographic characteristics may cause the response variable to vary.

A focus group is usually chosen to represent the venire, but the method of selection should depend upon your objective. In any case, select a focus group from either your sources or from The Decision Channel.

Your Focus Group. Your focus group can use the Internet version of FactLogic.

The Decision Channel's Focus Group. A focus group selected from The Decision Channel's registered users has these advantages:

Members have agreed to serve in focus groups for a reasonable fee.
Members have willingly supplied demographic information that is similar to that asked of potential jurors.
Members have used FactLogic software, having decided some public cases and possibly some private cases on The Decision Channel.

The possible disadvantage of selecting a focus group from The Decision Channel is that these members are not necessarily typical of a venire.

Size. The size of the focus group is determined by either

practical considerations (i.e., time or budget) or
desired precision.

The larger the focus group, the more precisely the margin can be known.

If you post a case for a focus group to decide using The Decision Channel, we supply a password for each member. It allows each member to access and decide your case in a secure and private Internet session. See Internet Focus Groups.

2. Determine the Variation of the Response Variable as a Function of a Characteristic

The following is an example of how the demographic characteristic, age, affects the margin. It shows that the margin is significantly different for two categories of age, and the predicted verdict is greatly affected by age.

Example. The son of a patient at Golden Homes LLC alleges that the company fraudulently sold a nursing home contract to his mother by grossly overstating the extent of care to be provided. Key evidence includes similar contracts between the company and seven other patients all of whose relatives claim the contracted service was not rendered. Select a focus group that can demonstrate the effect of the characteristic, age.

Compare the margin from two subgroups of the focus group.
Predict the general verdict from a jury of younger jurors and from a jury of older jurors; assume the general verdict requires concurrence of a majority of six jurors.

Solution (Compare the Margin from Two Subgroups). A focus group of 31 members was randomly chosen from automobile driver license holders in the venue in which the civil trial is scheduled. The size of the focus group was selected by budget constraints rather than by the desired precision. Since this is a civil case, the standard of proof was not asked of the members. (It would be necessary to obtain it in a criminal case.) The evidence, including the contracts, is listed with FactLogic. All members of the focus group gave the contracts a very high level of credibility (i.e. "Probability Fact is True" is nearly 100%). The real issue for the focus group is the probability that this fact proves liability. Not surprisingly, the 23 younger members of the focus group registered a significantly lower probability of liability for this evidence than did the eight members of the focus group in the 55 and older category. Specifically, the average probability of liability among the younger members is 40.246%, and the average probability of liability among the eight older members is 64.998%. In terms of the response variable:

The margin from the 23 younger members is 40.246% - 50% = -9.754%.
The margin from the eight older members is 64.998% - 50% = 14.998%.

Although these results are to be expected, the advantage of using FactLogic is that the judgments are quantified and additional analysis is possible. For example, due to the distribution of the probabilities comprising these two averages, a comparison test revealed that the margin from the two groups (i.e., 23 that are younger than 55 years and eight that are 55 years or older) are significantly different at the 5% significance level. That is, there is only a 5% probability that these two groups provide the same value of the margin. Age is a significant characteristic for this evidence, and older jurors should be selected for your client.

Solution (Predict the General Verdict from Each Subgroup). The predicted verdicts are extremely dependent upon age:

The margins among the 23 younger members averaged -9.754%, and analysis from FactLogic shows that the probability of a verdict For the Plaintiff from the younger members is less than 2.5%.
The margins among the eight older members averaged 14.998%, and analysis from FactLogic shows that the probability of a verdict For the Plaintiff from the older members is 94.3%.

3. Select Jurors from Knowledge Obtained from the Focus Group

The margin can vary with no demographic characteristic, one characteristic, or more. Sometimes analysis is quite complicated. In any case, use the knowledge you obtained from the focus group to select jurors.

Summary

Conduct an experiment that measures responses or predicts verdicts from a focus group that is selected according to specific values of characteristics, and select jurors based upon this experiment:

Define the following margin:

Margin = (Probability of Responsibility) - (Standard of Proof).

Select a focus group.
Identify demographic characteristics thought to be important to the margin.
Conduct an experiment to optimize the margin with respect to various demographic characteristics.
Let FactLogic predict the general verdict from subgroups selected according to certain values of the demographic characteristics.
Select jurors based upon the results of this experiment.

Footnotes

¹If applied to a civil case, the probability of responsibility is the probability of liability. If applied to a criminal case, the probability of responsibility is the probability of guilt.

[Return to Applications]