how accurately can laypersons predict factors that affect eyewitness testimony?

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How Accurately Can Laypersons Predict Factors That Affect Eyewitness Testimony?

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Page 1: How Accurately Can Laypersons Predict Factors That Affect Eyewitness Testimony?

How Accurately Can Laypersons Predict Factors That Affect

Eyewitness Testimony?

Page 2: How Accurately Can Laypersons Predict Factors That Affect Eyewitness Testimony?

Instructions

For this experiment, I’m going to give you descriptions of specific experimental conditions from an eyewitness study that was done in Victoria.

The descriptions on the slides are the same as the descriptions on the handouts.

Page 3: How Accurately Can Laypersons Predict Factors That Affect Eyewitness Testimony?

Instructions

After the description of each scenario, there are a few questions for you to answer.

Do not read ahead. Each scenario only takes one page.

If you have any questions, please ask the experimenter.

Page 4: How Accurately Can Laypersons Predict Factors That Affect Eyewitness Testimony?

The Original Experiment

A few years ago, 287 retail store clerks in Victoria were recruited to participate in a study to test their memory for customers. About once a week, they were to receive a phone call from a research assistant and would be asked questions about memorable customers of the day. They were told that a research assistant for the study would come down to the clerk’s store and explain the procedures more thoroughly before the phone calls began.

Two weeks after this first meeting, the store clerks were asked to identify the research assistant they had met from an 8-person photo lineup like those used by the police. There is an example of a photo lineup on the next slide.

Page 5: How Accurately Can Laypersons Predict Factors That Affect Eyewitness Testimony?

Lineup Example

Page 6: How Accurately Can Laypersons Predict Factors That Affect Eyewitness Testimony?

The Original Experiment

The store clerks tested were intended to be representative of store clerks in Victoria.

92 of the clerks were men and 193 were women. 2 clerks did not provide information about their gender.

The clerks had worked in retail between 1 and 33 years, with an average of 6.7 years.

Page 7: How Accurately Can Laypersons Predict Factors That Affect Eyewitness Testimony?

The Original Experiment

To begin the experiment, a female, Caucasian research assistant in her early 20s arrived at the store to give instructions for the study and to complete demographic questionnaires and informed consent forms. This meeting lasted about 10 minutes. Halfway through the meeting, fifty percent of the clerks were warned that at some point in the future they might be asked to give a physical description of the research assistant and identify her from a photo lineup like those used by the police. They were not told when this identification might occur. The other fifty percent of the clerks were told nothing about possibly being asked to describe and identify the research assistant.

Page 8: How Accurately Can Laypersons Predict Factors That Affect Eyewitness Testimony?

The Original Experiment

Julie, the Research Assistant

Page 9: How Accurately Can Laypersons Predict Factors That Affect Eyewitness Testimony?

The Original Experiment

Two weeks after the meeting, a male research assistant arrived at the store and asked the clerks to complete two 8-person photo lineups. The clerks were not told whether the lineups they were seeing contained a picture of Julie the research assistant or not. They had the option to indicate that Julie was not shown in the lineup. The photos in each lineup were of people who were similar in terms of gender, age, height, build, and hair colour.

Page 10: How Accurately Can Laypersons Predict Factors That Affect Eyewitness Testimony?

The Original Experiment

First, they were shown a lineup that did not have a picture of Julie, similar to a situation in which the police are pursuing an innocent suspect. The researchers wanted to determine how many of the clerks might falsely identify someone from a first lineup. The clerks were not given any feedback about how they had done on their identification. Afterward, they were shown a new lineup with all different photos that did have a picture of Julie.

Page 11: How Accurately Can Laypersons Predict Factors That Affect Eyewitness Testimony?

The Original Experiment

After each identification, the clerks were asked to rate their confidence in that decision on a 5-point scale, exactly like the one shown here:

Not at all sure Very sure

1 2 3 4 5

Page 12: How Accurately Can Laypersons Predict Factors That Affect Eyewitness Testimony?

This Experiment

Next are some descriptions of specific parts of experimental situations that clerks experienced as part of this research study. After the descriptions are some questions that ask you to give your best estimate about the results. Imagine that you are a juror in a trial, evaluating the testimony of a witness who made an identification under these types of circumstances. Please read the scenarios and questions carefully. When you have finished answering the questions from a scenario, put the completed page into the envelope before moving on to the next page.

Page 13: How Accurately Can Laypersons Predict Factors That Affect Eyewitness Testimony?

Scenario 1-A

Clerks were told that they were going to participate in a research study about store clerks’ memory for customers. Halfway through the first meeting with Julie, the clerks were warned that they might later be asked to identify her. Two weeks later, a male research assistant administered an 8-person lineup in which Julie was not present. The clerks were told that a photo of Julie may or may not be included in the eight photos. If the clerk believed that Julie was present, they were asked to give the number associated with her photo. If they believed she was not present, they were told to say “not present.” After they made a decision, they rated their confidence in that decision on the 5-point scale.

Page 14: How Accurately Can Laypersons Predict Factors That Affect Eyewitness Testimony?

Scenario 1-A

Key Points: Warned they might later have to identify Julie, two week delay before identification, 8-person lineup with no photo of Julie.

Page 15: How Accurately Can Laypersons Predict Factors That Affect Eyewitness Testimony?

The Lineups

The next slide shows a lineup that the clerks viewed in the study. In this lineup, Julie is absent.

Take your time viewing the lineup. When you are ready to go on, press the space bar to continue.

Page 16: How Accurately Can Laypersons Predict Factors That Affect Eyewitness Testimony?
Page 17: How Accurately Can Laypersons Predict Factors That Affect Eyewitness Testimony?

Scenario 1-A

Please answer the first page of scenario questions now.

When you are done, put the answer sheet in the envelope.

Page 18: How Accurately Can Laypersons Predict Factors That Affect Eyewitness Testimony?

Scenario 1-B

After completing the first lineup identification, the same clerks were administered a second, completely different 8-person lineup in which Julie was present. They did not receive feedback about the first lineup. Again, the clerks were told that a photo of Julie may or may not be included in the eight. If the clerk believed that Julie was present, they were asked to give the number associated with her photo. If they believed she was not present, they were told to say “not present.” After they made a decision, they rated their confidence in that decision on the 5-point scale.

Page 19: How Accurately Can Laypersons Predict Factors That Affect Eyewitness Testimony?

Scenario 1-B

Key Points: Warned they might later have to identify Julie, two week delay before identification, 8-person lineup with a photo of Julie.

Page 20: How Accurately Can Laypersons Predict Factors That Affect Eyewitness Testimony?

The Lineups

The next slide shows a lineup that the clerks viewed in the study. In this lineup, Julie is present.

Take your time viewing the lineup. When you are ready to go on, press the space bar to continue.

Page 21: How Accurately Can Laypersons Predict Factors That Affect Eyewitness Testimony?

Julie

Page 22: How Accurately Can Laypersons Predict Factors That Affect Eyewitness Testimony?

Scenario 1-B

Please answer the second page of scenario questions now.

When you are done, put the answer sheet in the envelope.

Page 23: How Accurately Can Laypersons Predict Factors That Affect Eyewitness Testimony?

Scenario 2-A

Clerks were told that they were going to participate in a research study about store clerks’ memory for customers. These clerks were not warned that they might later be asked to identify Julie. Two weeks later, a male research assistant administered an 8-person lineup in which Julie was not present. The clerks were told that a photo of Julie may or may not be included in the eight photos. If the clerk believed that Julie was present, they were asked to give the number associated with her photo. If they believed she was not present, they were told to say “not present.” After they made a decision, they rated their confidence in that decision on the 5-point scale.

Page 24: How Accurately Can Laypersons Predict Factors That Affect Eyewitness Testimony?

Scenario 2-A

Key Points: Not warned they might later have to identify Julie, two week delay before identification, 8-person lineup with no photo of Julie.

Page 25: How Accurately Can Laypersons Predict Factors That Affect Eyewitness Testimony?

Scenario 2-A

Please answer the third page of scenario questions now.

When you are done, put the answer sheet in the envelope.

Page 26: How Accurately Can Laypersons Predict Factors That Affect Eyewitness Testimony?

Scenario 2-B

After completing the first lineup identification, the same clerks were administered a second, completely different 8-person lineup in which the Julie was present. They did not receive feedback about the first lineup. Again, the clerks were told that a photo of Julie may or may not be included in the eight. If the clerk believed that Julie was present, they were asked to give the number associated with her photo. If they believed she was not present, they were told to say “not present.” After they made a decision, they rated their confidence in that decision on the 5-point scale.

Page 27: How Accurately Can Laypersons Predict Factors That Affect Eyewitness Testimony?

Scenario 2-B

Key Points: Not warned they might later have to identify Julie, two week delay before identification, 8-person lineup with a photo of Julie.

Page 28: How Accurately Can Laypersons Predict Factors That Affect Eyewitness Testimony?

Scenario 2-B

Please answer the fourth page of scenario questions now.

When you are done, put the answer sheet in the envelope.

Page 29: How Accurately Can Laypersons Predict Factors That Affect Eyewitness Testimony?

There is one last page of demographic questions for you to answer.

When you are done, please put all of the questionnaire sheets in the envelope and hand it to the experimenter.

Thanks!