Interviewing witnesses

Question 1

What was the aim in Bruce?

Answer 1

Investigate the relative recognisability of internal and external features in facial recognition.

Question 2

What was the method used in Bruce?

Answer 2

Lad based experiment, volunteer samples.

Question 3

What was the procedure used in experiment 1 in Bruce?

Answer 3

30pps (15F,15M) mean age 29.2, teachers and students at Stirling uni. Independent measures, 3 conditions. 10 celeb photos, 40 composite from E-fit, task was to match them up to celeb.
Group 1- Given complete composites
Group 2- Only internal features
Group 3- Only external features
Tested individually, asked to place composite in front of celeb in their own time.

Question 4

What happened in experiment 2 of the procedure for Bruce?

Answer 4

48 undergraduates at Stirling uni, 21M,27F. Used photo array of celeb faces, distracter faces included to make harder. Task to identify celeb composites.
The composites were presented one at a time along with the photo array of celebs.
Pps had to pick out the celeb face which matched each of the composites

Question 5

What were the results in experiment 1 in Bruce?

Answer 5

35% of completed composites were matched correctly but the external group.
Compared to 19.5% in the internal group.

Question 6

What were the results from the second experiment in Bruce?

Answer 6

External identified 42% of time,
compared to 24% of internal.
Pps got just above chance in internal.
Pps performed equally in full composite at external.

Question 7

What was the conclusion in Bruce?

Answer 7

External features more important for facial recognition, faces processed holistically.
New software uses E-fit and EvoFIT as both change faces holistically

Question 8

What was the aim in Loftus?

Answer 8

To provide support for the ‘weapon focus’ effect when witnessing a crime.

Question 9

What was the method Loftus?

Answer 9

Lab experiment

Question 10

Who were the pps in Loftus?

Answer 10

36 students from uni of Washington. Aged 18-31.
Half required via advertisement, paid $3.50.
Others were psychology students participating for extra credit.

Question 11

What was the procedure in Loftus?

Answer 11

All pps shown 18 slides of series of events in taco restaurant. Slides same for both groups except 1 slide= the IV.
Control group had the second person handing a cheque
Experimental group had same person with a gun.
Each slide was 1.5seconds. 20 multi questionnaire, also shown 12 head and shoulder photos as a line up. Eye fixation timed. Also asked to rate on scale of 1,guess-6, very sure if they think they correct identification

Question 12

What are the results in Loftus?

Answer 12

Answers to questionnaire had no significant difference in the groups.
Control group= 38.9 had correct identification (7ppl)
Experimental design= 11.1% (2ppl)
Eye fixation, gun= 3.72 secs to focus
Cheque= 2.44 secs
No difference in confidence level

Question 13

What was the conclusion from Loftus?

Answer 13

Longer time focus on weapon, which meant they had more difficulty in picking suspects in a line up.
This shows info gained from witnesses can be unreliable and crime involving weapon would affect ability to reconstruct suspects face.

Question 14

What was the aim in Fisher?

Answer 14

Compare the performance in a field of experienced detectives, pre and post training in cognitive interview techniques.

Question 15

What was the method used in Fisher?

Answer 15

Field with actual interviews and real witnesses.

Question 16

What was the sample in Fisher?

Answer 16

16 experienced detectives (at least 5 years) in Florida. 7 completed cognitive interview corse , compared to 9 untrained controls.

Question 16

What was the procedure in Fisher?

Answer 16

All 16 detectives tape recorded several interviews using standard interview techniques. Between 5-7 over a 4month period, totalling 88interviews. Mainly robbery or Purse snatching.
2 groups created, 7 did 4, 1 hour sessions in cognitive interview tech.
These and 6 out of 9 or control group recorded 2-7 interviews over 7months. Judges judges number of relevant, factual and objective statements recorded, blind to each condition, from uni of California.

Question 17

What were the results from Fisher?

Answer 17

47% more info recorded post training interviews by CI trained.
63% more info recorded by trained than non trained.

Question 18

What was the conclusion from Fisher?

Answer 18

CI training is very effective compared to normal, also easy to provide.