Transcript Loftus & Palmer

AS Level Psychology
The core studies
Cognitive Approach
Eye Witness Testimony
Traffic accident clips
Traffic Accident Questions
• Clip 1: Who was responsible for the accident?
• Clip 2: What was the weather like?
• Clip 3: About how fast in miles per hour was the car
going when it smashed into the bus?
• Clip 4: What was the colour of the car out of
control?
• Clip 5: Which way did the car skid first?
• Clip 6: Did the car have an amber or a green light
at the junction?
• Clip 7: Which part of the red car was damaged?
Eye Witness Testimony
• The study of human memory is a research area in
cognitive psychology
• Eye witness testimony involves memory!
Eye witness testimony?
• Elizabeth Loftus & John Palmer tested the reliability
of eye witness testimony
• Can the memory of an event be changed by the
way witnesses are questioned?
• The effect of leading questions
Loftus & Palmer
Class discussion:
• What is a leading question ?
Do we agree that
• Memory is not like a camera - we always
reconstruct our memories
Loftus & Palmer
• The title of their paper
was: The reconstruction
of an automobile
destruction
• Their research involved
two experiments
Loftus & Palmer
Experiment 1
• The participants - 45 students
• The procedure - Students watched film clips of car
accidents
• After watching the films the students were asked to
do two things
Loftus & Palmer
Experiment 1
1. Write an account of what they had seen
2. Answer questions about what they had seen
One question was the critical question
Loftus & Palmer
Experiment 1
The Critical Question
About how fast were the cars going when they
(*******) each other?
There were five conditions (verbs) in the
experiment (Five groups of students)
Loftus & Palmer
Experiment 1
The five conditions
(verbs)
Were:
1. Contacted
2. Hit
3. Bumped
4. Collided
5. Smashed
Loftus & Palmer
Experiment 1
Expt 1: Estim ated Speed for Verb Used
45
35
30
25
as
he
d
Sm
ed
lid
Co
l
pe
d
Bu
m
Hi
t
20
Co
nt
ac
te
d
Speed
40
Loftus & Palmer
Experiment 1
• What conclusion can you draw from the findings?
• What was the IV?
• What was the DV?
Eye Witness Testimony
The second experiment
by
Loftus & Palmer
Loftus & Palmer Experiment 2
• The participants - 150 students
• The procedure - Students watched a one minute
film which showed a 4 second multiple car
accident
Loftus & Palmer Experiment 2
After the film the participants were divided into
three experimental groups
Loftus & Palmer Experiment 2
Group 1 was asked:
“How fast were the cars going when they
hit each other?”
Loftus & Palmer Experiment 2
Group 2 was asked:
“How fast were the cars going when they
smashed into each other?”
Loftus & Palmer Experiment 2
Group 3 was asked no question about the speed
of the cars
Loftus & Palmer Experiment 2
One week later
• The participants returned and were asked more
questions including the critical question
“Did you see any broken glass?”
Loftus & Palmer Experiment 2
Expt 2: Response to "Did you see any
broken glass"
No. of Responses
The findings
• Which group
saw more
broken glass?
50
40
30
20
10
0
Yes
No
Smashed
Hit
Control
Loftus & Palmer Experiment 2
• What was the DV in the second experiment?
• What conclusion can you draw from the findings?
• Complete a card sort to identify which results and
conclusions link to experiment 1 and which results
and conclusions link to experiment 2.
• You will be provided with cards with information on
both experiments and some ‘red herrings’ too!
• In pairs you need to organise the cards logically in
sequence and into the three groups;
1. Results & conclusions from experiment 1
2. Results & conclusions from experiment 2
3. Red herrings!
Results from exp 1:
Verb Used
Speed
estimation
2
conclusions
Results from exp 2:
Verb Condition
Plus 6 red
herrings!
Number of
participants
that saw broken
glass
% that saw
broken glass
Results from exp 1:
Results from exp 2:
Verb Used
Speed
estimation
2 conclusions
Verb Condition
Number of
participants
that saw broken
glass
% that saw
broken glass
Smashed
40.8
Response
Bias
Smashed
16
32%
Hit
7
14%
Control
6
12%
Collided
39.3
Bumped
38.1
Hit
34
Contacted
31.8
Memory
alteration caused
by schema
provoked by the
word used
Plus 6 red
herrings!
•Confirm your card sort is correct by your teacher
•Use this information to complete the Core study worksheetcomplete the charts using this information
•Answer the questions about the conclusions that can be drawn
from the study
Loftus & Palmer
• Was this research in any way unethical?
• Did this research have ecological validity?
• Was this a repeated measures design
or an independent measures design?
Loftus & Palmer
• Read the study
• In your general text, read up on what psychologists
say about human memory
• According to Loftus & Palmer (in the 2nd
experiment) how did the leading question ‘change’
the memory ?
Eye Witness testimony
• Do you think that
unsupported eye
witness testimony
should be sufficient
evidence upon which
to convict someone?