Loftus and Palmer

• aim of loftus and palmer study

  -to investigate the effect of leading questions on eye witness testimony of car crashes

  -can memory of an event be changed by the way witness' are questioned?
• method of loftus and palmer

  2 lab experiments- independent measures design
• sample of loftus and palmer

  -45 students, split into 5 groups (experiment 1)

  -150 students (experiment 2)
• variables of loftus and palmer

  IV- hit smashed collided bumped contacted

  DV- estimate of speed (e1) or if they saw smashed glass (e2)
• procedure 1 of loftus and palmer

  -student watched 7 film clips of car accidents from a safety training film

  -after watching they had to:

  write and account of what they had seen / answer a questionaare with the critical question of 'what speed were the carts going when they ____ into each other
• procedure 2 of loftus and palmer

  -one minute film which shows 4 car crashes

  -after film group split into 3 groups, 2 experimental and 1 control

  -group 1: how fast were the cars going when they hit each other

  -group 2: how fast were the cars going when they smashed into each other

  -group 3: no question about the speed of the cars (control)
• results of E1

  -smashed- 41

  -collided- 39

  -bumped-38

  -hit- 34

  -contacted- 32
• results of E2

  did you see any broken glass?

  yes: smashed (16), hit (7), control (6)

  no: smashed (34), hit (43), control (44)
• conclusion of loftus and palmer

  -how the question was phrased influenced the participants speed estimates

  -when 'smashed' was used, participants estimated the car was travelling faster

  -poeple not very good at estimating speeds of cars

  -the way the question is asked can influence the answer given

  -suggest the leading question had actually altered the participants memory of the event
• how does loftus and palmers study link to the cognitive area

  -schema: verb changed affects speed estimated

  -study of memory and perception
• validity loftus and palmer

  -good internal validty (good controls, tests what it wants to test)

  -poor ecological validity (cant generalise situation to real life, low emotional arousal)
• type of data loftus and palmer

  -quantitative data (estimated speed, seen glass or not)
• practicle applications loftus and palmer

  -shows how leading questions can effect a persons memory

  -explains how eye witness testimony questions influence memory (effect on justice system)
• reliability loftus and lamer

  -only manipulate the verb

  -good reliability

  -standardised

  -lots on controls

  -can repeate to get the same results
• research method loftus and palmer

  -lab experiment

  -control over extraneous variables

  -may have demand characteristics (which are minimised by using and independent measures design)
• sampling bias loftus and palmer

  -not representative, only consists of university students (they're used to being tested + not much experience driving)
• ethnocentrism loftus and palmer

  -american university, same unreliable memory
• ethics loftus and palmer

  -protection from harm (no stress)

  -informed consent as they are volunteers

  -some deception as they didn't know they critical question