G543 - Interviewing Witnesses - Bruce Et Al Flashcards
(22 cards)
How many lab experiments were there in total?
3
How many participants were ther in experiment 1? How much did they get paid? What was their mean age?
30 students (15m 15f). Paid £2. Mean age 29.2
In experiment 1, how many composite images were created from how many photographs of celebrities?
40’composites from 10 photographs
In experiment 1, who were the composites made from? Using what software?
Made from celebrities using E-Fit, Pro-Fit sketch and evo fit
In experiment 1, what were the three conditions participants were tested individually on?
Complete set, internal features only and external features only
In experiment 1, what were the pps asked to do in their assigned groups?
Asked to place each composite in front of the celebrity face in their own time until the task was finished
What was the sample in experiment 2?
48 undergraduates at striking university (27 males 21 females). All volunteers
What did experiment 2 consist of?
A photo array with distraction faces making the task more difficult
In experiment 2, what was made easy or hard!
Faces and foils. Easy - faces and foils all very different. Hard - faces and foils all very similar
In experiment 2, how were the composites presented?
One at a time along with the photo array
In experiment 2, what did the participant have to do?
Pick out the celebrity face from the array that matched the composite
In experiment 2, what were the two types of composite?
Internal or external features (like experiment 1)
In experiment 3, how many staff were recruited. To be what? How much were they paid?
8 staff paid £10 to be participant witnesses
In experiment 3, how many volunteers did a sorting task and how many did a naming task?
Sorting task - 54
Naming task - 16
In experiment 3, what was presented to the witnesses?
Familiar or unfamiliar faces
In experiment 3, what did the witnesses have to do after being presented with the familiar or unfamiliar faces?
Create pro-fit composites after seeing the faces for 30 seconds
In experiment 3, what happened after the witnesses had made the pro-fit composites?
They were then photoshopped to create internal and external only composites which were then randomly presented to the sorters and the namers alongside while faces as before
Experiment 1 results:
- Whole composites and those of external features were sorted similarly at what percentage?
- what percentage were internal features sorted at?
35% correct
19.5% correct
Experiment 2 results:
Composites of …. Were identified more easily than …
What was this consistent across?
- external features (42%). Internal features (24%)
- array type (whether easy or difficult)
Experiment 3 results:
What % was sorting accurate at?
What did it not matter whether the face were?
What features were more accurate than what?
How accurate was the naming task?
- 57%
- familiar or unfamiliar
- external more accurate than internal at 53.3% against 32.6%
- 22% accurate whether face was familiar or unfamiliar
What did Bruce et al conclude participants performed equally well with? Which could indicate what?
External features and whole faces which could indicate that there is something about internal features of a face that does not work well when trying to create a reconstruction.
What did they aim to investigate?
The relative recognisability of internal and external features of facial composites
