EVALUATION OF LOFTUS & PALMER - 30.03.2010

EVALUATION pg. 20

Laboratory Experiment
What are the strengths & Weaknesses?

(Relate strengths and weaknesses to the core study)

V-RED
• Variables, Replication, Ecological Validity, Demand Characteristics

STRENGTHS
V = Variables
Loftus & Palmer did this is in a controlled condition. Therefore allowing them to determine the cause and effect i.e words used in the questions caused differences in recall.

R = Replication
Because it was conducted in a laboratory experiment, any interested investigators who wish to further investigate Loftus & Palmer study can easy replicate the study.

Weaknesses
E = Ecological Validity
• Loftus & Palmer’s study used artificial situation therefore generalizing the results to real life would be an issue = low ecological validity.

D = Demand characteristics
• Participants probably looked for clues on how to behave and will try to give Loftus & Palmer answers they were looking for.

EVALUATION NO. 2

Only collected QUANTITATIVE DATA
strengths
- What is the problem with collecting quantitative data?

- Do you think qualitative data would benefit the experiment more?

EVALUATION NO. 3

WHAT IS THE DIFFERENCE BETWEEN WATCHING A CAR ACCIDENT IN REAL LIFE AND ON TV?


On Tv
- Less Distressing
- Expected to be asked questions about it, therefore watched the TV differently (intention-wise)

In Real-life
- Quite distressing (increase in emotion = fear, shock)
- May not be paying attention at first = element of surprise

EVALUATION NO. 4

SAMPLE: Students
Not representative of the general population

Can you apply the results of the students to all AGE groups?

The problems:

• Young therefore possible that they might have better memories

• Used to absorb information and then being asked questions about it.

• Less experienced drivers = less accurate in estimating speed

• Demand Characteristics?

Practical applications:

• Interviewing witnesses (both by police and lawyers) soon after an event

• Interviewers should avoid leading questions

• Educational setting?

LOFTUS & PALMER CORE STUDY - 30TH & 31ST MARCH 2010

30th and 31st March 2010

How to look at each core study
Divided into sections:
1.) Title
2.) Author
3.) Key Words
4.) Aim
5.) Sample
6.) Method
7.) Results
8.) Conclusions
9.) Issues / Implications

TITLE: Reconstruction of automobile destructionLOFTUS & PALMER (1974)

Key Words:
• Memory is prone to CHANGES!

• Eye witness testimony

• Leading Questions
•
Leading Question:
Question that suggests the answer or contains the information the examiner is looking for.

Example of a leading question:
“You were at Duffy's house on the night of July 15, weren't you? “

Example of a NON-LEADING question:
“Where were you on night of July 15?”

LABORATORY EXPERIMENT WITH TWO STUDIES

STUDY 1
AIM
To see the effect of language on our memory
HYPOTHESIS:
No explicit hypothesis.
But by implication, verbs used are expected to produce higher esimate of speed.

Definition of Hypothesis:
A testable prediction about the relationship between at least two events, characteristics, or variables.

VARIABLES:
IV: 5 Verbs used in question
Smashed, hit, collided, contacted and bumped
DV: Estimated Speed of the vehicles


SAMPLE / PARTICIPANTS:
45 students

DESIGN:
Independent Measures Design (RESEARCH MORE!)
• 2 or more separate groups, each containing different individuals, where each participant only takes part in each condition once.

Advantages:
• No order effects because participants are only taking part in one condition.
Participants performing differently because of the order in which the conditions are performed.
• More participants are used therefore increases external validity of the experiment

Disadvantages

• Lacking control over participant variables = Potential of errors occurring from individual differences of participants in each group, affecting the results

METHOD / PROCEDURE:
7 clips of traffic accidents
(Safety clips for driver’s education)
Questionnaires:
‘give an account of the accident you have just seen’.
Specific questions
Critical Question:
“How fast were the cars going when they _ _ _ _ each other”.

45 Participants were divided into 5 Groups/Conditions therefore 9 students per group

Different VERBS were used for each group.

Group 1: How fast were the cars going when they SMASHED each other

Group 2: How fast were the cars going when they COLLIDED each other

Group 3: How fast were the cars going when they BUMPED each other

Group 4: How fast were the cars going when they HIT each other

Group 5: How fast were the cars going when they CONTACTED each other
RESULTS:

Smashed : 40.8 (highest)
Collided: 39.3
Bumped: 38. 1
Hit: 34. 0
Contacted: 31.8 (lowest)

INTERPRETATION:
‘Smashed’ had higher estimates of speed than ‘contacted’.

CONCLUSION:
Leading questions AFFECT recall.

HOW LOFTUS & PALMER EXPLAINED THESE RESULTS:

1.) The verb actually distorts memory
2.) Response bias factors (an example of demand characteristics).

STUDY 2

HYPOTHESIS:
Participants asked about the speed of the cars that ‘smashed’ would be more likely to say they had seen broken glass than participants who were asked about the cars that ‘hit’.

SAMPLE/PARTICIPANTS:
150 students

METHOD / PROCEDURE:
One-minute film (4 seconds of multiple car accidents).

Students divided into 3 groups (50 students per group).

VARIABLES:
IV: verbs used in Question
Smashed / hit
DV: if they saw broken glass

GROUP 1:
‘How fast were the cars going when they HIT each other?”

GROUP 2:
‘How fast were the cars going when they SMASHED each other?’

GROUP 3:
No question (control group).

Definition of Control group
A group that is similar to the experimental group and is expose to the same experimental environment but is NOT exposed to the independent variable; the group is used for comparison

ONE WEEK LATER

Participants were asked further questions (Without viewing videos again).

Critical Question:
‘Did you see any broken glass’.

FYI: No broken glass!

RESULTS:

‘Smashed’ group:
16/50 said YES
34/50 said NO

‘Hit’ group
7/50 said yes
43/50 said no

Control group:
6/50 said yes.
44/50 said no

CONCLUSION:

The word ‘smashed’ sounded MORE SEVERE than ‘hit’ therefore..

The participants in the ‘severe’ group were twice as more likely to report seeing broken glasses.


RECONSTRUCTIVE HYPOTHESIS

Loftus & Palmer suggests two kinds of information go into a person’s memory:
1.) Information obtained from PERCEIVING the event
2.) Information obtained AFTER the event