Cognitive Approach- Classic Research

Question 1

Loftus and Palmer- Method

Answer 1

Method: The study consists of two experiments conducted in a lab using an independent groups design.
Experiment 1 method: Sample- 45 American university students, Lab/controlled experiments, film, questionnaire, manipulation of independent variable-verbs.
Experiment 1 procedure: PPS were shown 7 films of car accidents lasting between 5-30secs. Given questionnaire with various questions to give account of the film, including critical question. Experiment lasted 1.5 hours. Different ordering of films presented by each group.

Experiment 2 method: Sample- 150 methods into 3 groups. Film of multiple car accidents. Questionnaire.
Experiment 2 procedure: Shown film of car accident. Lasted less than 1 min & accident was 4 secs. Given questionnaire to describe accident plus main question. 50 PPS- about how fast the cars were going when they smashed into each other. 50 PPS- hit. 50 PPS- control. One week later. With watching film again- ‘Did you see any broken glass?’ question embedded in 10 questions. Was no broken glass.

Question 2

Findings

Answer 2

In experiment 1, the mean speed estimate for the ‘smashed’ group was 40.8mph. ‘Collided’ group was 39.2mph. ‘Bumped’ group was 38.1mph. ‘Hit’ group was 34mph. ‘Contacted’ group was 31.8mph. In experiment 1, Loftus & Palmer concluded the form of a question can markedly & systematically affect a witness’ answer to the question.
In experiment 2, Participants gave higher speed estimates in the ‘smashed’ condition. Participants returned a week later. Group 1 ‘smashed’ condition: 16 reported having seen broken glass; 34 reported not seeing any. Group 2 ‘hit’ condition: 7 reported seeing glass; 43 reported not seeing any. Group 3 control condition: 6 reported seeing glass and 44 reported not seeing any.

Question 3

Conclusions

Answer 3

In conclusion experiment 1 found that the hasher the verb sounded, the higher the pps would estimate the speed at which the cars would hit

Question 4

Evaluation- Methods and Procedures

Answer 4

Strength-Controlled Experiment-Reliable- Loftus and Palmer conducted their research using experiments.
Standardised procedure - another researcher can repeat study
-it has been replicated by other researchers many times and results have been found to be consistent
-suggests that findings are not just due to chance but are meaningful
-supports Loftus’ conclusion about the effects of leading questions on memory

Methodology and procedures - ecological validity
weakness - low ecological validity
-watching films is not the same as witnessing a car accident so it may not be applicable to real world
-participants knew they were in a study so may not take it as seriously
-not emotionally aroused as not happening in real life
-in real life, EWT may be more accurate

Methodology and procedures - the sample
weakness - sample of participants
-participants were US college students
-sample may not be representative of target population and so may not be generalisable

Methodology and procedures - controlled experiment
strength - controlled
demonstrates causal relationship as when deliberately manipulating IV we can see how causal effect on DV and draw casual conclusion
-lab experiment - confounding variables are carefully controlled and so does not influence results

Question 5

Alternative Evidence

Answer 5

Alternative evidence - Loftus (1979)

• showed participants pictures of man stealing woman’s bag - 98% were able to identify colour of bad correctly and they persisted after enduring leading questions
• contradicts Loftus and Palmer - leading questions have limited effect on memory in some circumstances BUT this may be because colour of bag is less subjective than estimate of speed

Question 6

Ethical Issues

Answer 6

Ethical issues and social implications - deception and informed consent

• informed consent is very important in psychological research but in this study, participants were deceived about the aims of the study
• they were deceived as to not influence answers and thereby cause lack of validity
• Believe this to be justified as it is only mild deception as there was likely no harm

Ethical issues and social implications - psychological harm
criticism = participants watched films, not a real-life car accident so they would not respond to task in the way an eyewitness would in a real crime
Alternative may have been to expose them to a real-life car accident, could be distressing and lead to psychological harm
-this study avoided this ethical issue by using films - limited harm
-EWT needs to be questioned more thoroughly
-jury/lawyers need to be aware of EWT limitation