Download your Class experiment packet.

For some people, the picture doesn't download with the rest of the experiment package. If this happens to you, click this link and then print out the screen.

• Loftus and Palmer (1974). Reconstruction of automobile destruction: An example of the interaction between language and memory. Journal of Verbal Learning & Verbal Behavior, 13, 585-589.
• Bell and Loftus (1989). Trivial persuasion in the courtroom: The power of (a few) minor details. Journal of Personality & Social Psychology, 56, 669-679.
• Shaw, Garcia, and McClure (1999). A lay perspective on the accuracy of eyewitness testimony. Journal of Applied Social Psychology, 29, 52-71.

These articles are on reserve at the Psychology Resource Center (rm 17 basement of DeGarmo). They will also be available at the reserve desk (an maybe on-line if things are fixed), but this sometimes takes a while).

What follows is a brief review of these three articles. For your written paper, you should read all three of these articles and include some discussion/description of them in the introduction section of your paper. Additionally you should find two more related articles, and include them in your introduction as well.

Remember that the description here should give you some orientation to the articles, BUT you need to read all of the articles to be able to write a good paper

(1) Loftus and Palmer (1974)

Purpose: determine what factors influence eyewitness testimony

EXP 1

Method: subjects viewed films of traffic accidents and then judged the speed of the cars at impact with 5 different verb descriptors used in the questioning
• What kind of data collection method is this? (naturalistic observation, archival, systematic observation, or survey/interview)
  systematic observation

• IV?
  Verb descriptor (smashed, collided, bumped, hit, contacted)

• DV?
  Speed judgment

  Results: verb descriptor affected the speed judgments

  Verb Mean Speed Estimate (mph)

  smashed	40.8
  collided	39.3
  bumped	38.1
  hit	34.0
  contacted	31.8

EXP 2

Method:

• subjects viewed film of car accident
• half questioned about speed with "smashed" or "hit"
• after a week were asked more questions, including "Did you see any broken glass?"

  Results:

• speed: smashed > hit
• yes responses: smashed > hit

  Conclusions:

• single word change in questioning of witnesses can change their response
• change in wording can also cause them to remember something that wasnÕt there (up to a week later)
• eyewitness reports can be influenced by wording of questions asked

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(2) Bell and Loftus (1989)

Purpose: how much are people (e.g., jurors) influenced by the detail provided by witnesses - trivial persuasion

EXP 1

Method:

• subjects read the transcript of a court case that included a defense witness and a prosecution witness
• subjects had to act as jurors and decide guilt of defendant and credibility of the eyewitnesses
• level of detail was manipulated for each witness (low/high)
• relevance of detail was also manipulated (related to crime/unrelated)

  Results:

• high detail for prosecution witness caused more ÒguiltyÓ verdicts (high > low)
• importance of relevance of detail in this effect depended on level of detail for defense witness (if defense witness had low detail, unrelated detail for the prosecution was valued)
• high detail made the witness appear more credible (high > low)

EXP 2
Method: same as Exp1, but only detail for defense witness was manipulated (low/high) and verification was manipulated from the prosecution witness by a detail question

Results:

• fewer "guilty" verdicts with high detail for defense witness (high < low)
• larger difference (high < low) when prosecution witness was shown to have low detail

  Conclusion:

• juror decisions are influenced by the detail provided by the witnesses, even if the detail isnÕt directly relevant to the crime

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(3) Shaw, Garcia, and McClure (1999)

Purpose: examine what people think affects the accuracy of eyewitness testimony

Method:

• two questionnaires were given to groups of subjects
• Q1 - imagine they are jurors and list things that they think would affect accuracy of eyewitnesses for 6 categories
• Q2 - similar to Q1, but no categories given

  Results:

• factors about the eyewitness, crime scene, and suspect were listed most often in Q1
• police procedures (i.e., questioning) was listed least often in Q1
• same results for Q2, but stronger - police procedures only accounted for 1% of responses

  Conclusions: people donÕt generally seem aware that questioning affects witness accuracy - juror decisions may not be affected by such factors

These articles will be the sources for your research paper - you will be required to discuss and cite them in the paper as part of the assignment Not limited to just these articles - you can find others to help support purpose of our study and our hypotheses - But you must at minimum cite these articles to write a good paper

Please run one male subject and one female subject through the following procedure. Run the subjects one at a time. The subject's participation is voluntary. Please follow all ethical guidelines in the treatment of your subjects. If a subject wishes to discontinue the experiment at any time, you must allow them to do so. Make sure each subject signs the consent form. You may not run any subject until they sign the consent form. After they sign the form, read the instructions printed below out loud. The instructions are also printed on their sheet so they can follow along as you read them. Ask the subject if they have any questions and if they do, answer them before they begin. Give the participant the scenario (and the picture for 1 of your participants). Then allow the subjects to read the scenario to themselves and proceed through the procedure at their own pace. Allow them as much time as they want to make their responses. After they make their responses, read the debriefing statement printed below out loud. Answer any questions the subjects may have and then collect their response sheet. Mark on the response sheet whether they did or did not view the picture. Fold the response sheet and staple it shut. Keep the consent forms and response sheets separate to protect the anonymity of the subjects.

Give them a copy of the consent form and have them read and sign it BEFORE they participate.

We are interested in studying the manner in which people use information to make judgments about responsibility for accidents. You will be asked to read a brief eyewitness account of a car accident. When you have finished reading the account, you will be asked to give your personal opinion concerning the case. That is, we want you to determine how much Òat faultÓ you think one of the drivers is. WeÕll also ask you about some of the details about the accident. After you make your sentence recommendation, please rate the defendant and the victim, using the 7-point scale provided. Take as much time as you want to read and contemplate the case before making your responses. Remember that we are interested in you personal opinion, so please give your own personal judgment and not how you feel others might react to the case or how you feel you should react to it. Your honest impressions will be appreciated.

2 (piture: present/absent) x 3 (verb type: bump, contact, smash)

	bump	contact	smash
with picture	A1	B1	C1
without picture	A2	B2	C2

"I was standing on the Northwest corner of the intersection. Car 1 was approaching the intersection from the North at about 30 mph. Car 2 was approaching the intersection for the East at about 30 mph. Neither car slowed as they approached the intersection. Car 1 (smashed/bumped/contacted) Car 2 as it was going through the intersection. I think Car 1 may have been running a red light."

Response Form Instructions Assume that you are a member of a jury hearing a case regarding the responsibility of the people involved in the accident. Please answer the questions below based on your impression of the eyewitness testimony you just read. (1) Please rate how much you think Car 1 is responsible ("at fault") for the accident based on the eyewitness account you just read. [circle one]

1              2              3              4              5              6              7
Not			       		 Equally			    		Completely 
at fault			       	at fault		         		at fault
				       	with car 2		                      

1              2              3              4              5              6              7
Not at			        	  Possibly	      			     Completely 	
all sure		              	    sure				       sure

1             2              3              4              5              6              7
There defineitely								   There definitely
Was not					            				    was  broken
Broken glass					             			      glass
		                      

1              2              3              4              5              6              7
Not at			        	  Possibly	      			     Completely 	
all sure		              	    sure				       sure

Thank your for your participation.

The experiment you have participated in was designed to examine factors involved in the decision-making processes of juries. In particular, we are interested in the ways in which eyewitness testimony and affects juror judgments of responsibility for an accident. We are not interested in the responses of any one participant. Instead, we are only interested in the average responses of all participants in the study. No identifying marks accompany your data; therefore, no one will ever be able to know what responses you made. If you wish to learn more about this study, please contact Dr. Cutting at jccutti@ilstu.edu or 438-2999. Thank you very much for participating.

Here are the results of the experiment.