Loftus and Palmer (5)
Experiment 2 - Results:Response: (Yes) Smashed = 16; Hit = 7; Control = 6 / Response: (No) Smashed = 34; Hit = 7; Control = 44. These results show a signficant effect of the verb in the question on he mis-perception of glass in the film. Evaluation: Strengths: Experiments allow for precise control of variables. The purpose of control is to enable the experimenter to isolate the one key variable which has been selected (the IV), in order to observe its effect on some other variable (the DV). Control is intended to allow us to conclude that it is the IV, and nothing else, which is influencing the DV (i.e a cause and effect relationship). e.g. Loftus was able to control the age of the participants, the use of video and the location of the experiment. All participants were asked the same key questions (apart from changes in the critical words), and the position of the key question in the second was randomised. This allows us to conclude that it was in fact the use of leading questions that caused the change in speed estimates. Weaknesses: The experiment lacks ecological validity as it doesn't reflect real-life situations. The experiments were carried out in artificial environments by Loftus and they're artificial in that they're different from how people would normally witness events. e.g. when the participants were given speed estimates of speed, they didn't have any personal involvement in the judgement or had taken any part in the event. When we witness events in everyday we have some involvement in the people or action... Its difficult to generalise findings from a lab setting to a real-life situation. A further problem with the study was the use of student participants. Students may be very different to other people. e.g. students are used to remember lots of info, and are usually good at memory tasks compared to other people. Also, not everyone who witnesses a real-life event is a student, so the results can't be generalised to all eyewitnesses.