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Background:
Theories:
Theories:
EXPERIMENT 1)
Aim: Research method: Lab Experimental Design: IV: verb used in the critical question (smashed, collided, hit, bumped, contacted) DV: estimated speed the cars were travelling at the time of the incident Sampling Technique: Sample: 45 students Procedure: Ps were divided into 5 groups. All ps were shown the same seven film clips of different traffic accidents which were originally made as part of a driver safety film. After each clip ps were given questionnaire which asked them firstly describe the accident and then answer a series of specific questions about the accident. There was one critical question - ‘About how fast were the cars going when they hit each other?’ One group of participants was given this question whilst the other four were given the verbs ‘smashed’, ‘collided’, ‘bumped’ or ‘contacted’ instead of the verb ‘hit’. Results: Conclusions: |
EXPERIMENT 2)
Aim: Research method: Lab Experimental Design: IV: verb used in the critical question (smashed, hit, no question about speed) DV: whether or not participants recalled seeing any broken glass Sampling Technique: Sample: Procedure: Ps were divided into 3 groups. All ps were shown a one-minute film which contained a four-second multiple car accident. They were then given a questionnaire which firstly asked them to describe the accident and then answer a set of questions about the incident, including a critical question about speed where one group was asked ‘About how fast were the cars going when they ‘smashed’ into each other?’ another group were asked ‘About how fast were the cars going when they ‘hit’ each other?’ and the third group did not have a question relating to vehicular speed. One week later ps returned and without seeing the film clip again completed another questionnaire about the accident which contained the further critical question ‘Did you see any broken glass?’ There had been no broken glass in the original film. Results: Conclusions: |
Evaluation:
Research Method: (Lab)+ = Because the IV – the verb in the critical question (smashed, hit, collided, bumped, contacted) – could be manipulated to observe its effect on the DV – speed estimates – causal relationships could be demonstrated ie Loftus and Palmer were able to show that the verb in the leading question influenced speed estimates given by participants
+ = Because variables can be controlled, cause and effect can be inferred. Here the controlled showing of the videos, standardised format of the questionnaires etc allowed Loftus and Palmer to conclude that it was the verb in the leading question that influenced the speed estimates given.
- = Because lab experiments lack ecological validity. It is not usual to sit and watch videos of car crashes and then complete questionnaires relating to the car crashes. There is a lack of realism/this does not reflect a real life situation
- = Because the artificial, contrived environment led the participants to respond to demand characteristics, giving an answer they think the researcher wants rather than their own opinion. Here participants, especially as they saw 7 clips in Experiment 1, may have worked out that Loftus and Palmer were looking to see the effect of leading questions and so gave a speed estimate in accordance with expectations.
Sample:
Reliability:
Validity:
Usefulness:
Ethical Issues:
Improvements & Implications:
Research Method: (Lab)+ = Because the IV – the verb in the critical question (smashed, hit, collided, bumped, contacted) – could be manipulated to observe its effect on the DV – speed estimates – causal relationships could be demonstrated ie Loftus and Palmer were able to show that the verb in the leading question influenced speed estimates given by participants
+ = Because variables can be controlled, cause and effect can be inferred. Here the controlled showing of the videos, standardised format of the questionnaires etc allowed Loftus and Palmer to conclude that it was the verb in the leading question that influenced the speed estimates given.
- = Because lab experiments lack ecological validity. It is not usual to sit and watch videos of car crashes and then complete questionnaires relating to the car crashes. There is a lack of realism/this does not reflect a real life situation
- = Because the artificial, contrived environment led the participants to respond to demand characteristics, giving an answer they think the researcher wants rather than their own opinion. Here participants, especially as they saw 7 clips in Experiment 1, may have worked out that Loftus and Palmer were looking to see the effect of leading questions and so gave a speed estimate in accordance with expectations.
Sample:
Reliability:
Validity:
Usefulness:
Ethical Issues:
Improvements & Implications: