practical Flashcards
state the aim of the practical
- investigate whether there are differences in the number of ppts who respond correctly to a leading or non leading question about identification in EWT
state the operationalised IV
response to the critical question, whether this was a leading or non leading question
- what hand was the magnifying glass in?
- what was the policeman holding?
state the operationalised DV
number of correct answers for a leading or non leading question about identification
why is a 1 tailed hypothesis used?
past research has shown that there will be a significant difference
state the alternative hypothesis
there will be more incorrect responses to the critical question when a leading question is used about identification, compared to when a non leading question is used
state the null hypothesis
there will be no significant difference between the number of correct responses to a leading or non leading question about identification. any difference will be due to chance
describe the method
laboratory experiment
- classroom: controlled and artificial
describe the sample
- opportunity
- 17-18 year old psych students from King Eds
describe the design
- independent measures
- quick and efficient
- no demand characteristics
- however, individual differences affect this
describe the apparatus used
- 2 min whodunnit clip
- prevents loss of concentration and distractions
- large screen
- pen and paper
- 5 questions designed after watching the video
summarise the procedure
- gain informed consent from ppts by explaining aims,right to withdraw, confidentiality
- watch 2 min EWT video in silence
- recall everything from clip in 5 mins
- group A given leading q, B given non leading q - 2 mins to answer
- 10 min psychology qs interference task
- all given the non leading q
- given full debrief
state and explain 3 controls
- all ppts answered 5 qs
- same position of leading qs - all ppts viewed a video clip
- full focus, no distraction, not in peripheral view - tested in a classroom
- controlled and quiet, ppts had not seen the video before
describe the ethics
- not a distressing clip
- protected from harm
- however, makes it less realistic
state the percentage of correct answers in the leading question condition
37.5%
state the percentage of correct answers in the non leading question condition
50%
what stats test was used?
chi squared
why was the chosen stats test used?
- test for difference
- independent measures
- nominal data
what was the observed value compared to the critical value?
- 0.32
- 2.71
- so not significant
describe the conclusion
- not significant results
- null hypothesis accepted
- did not support most previous research but does support Yuille and Cutshall
describe the generalisability
- high as memory is universal
- low as psychology students may have previous knowledge and could be a motivated sample
- low as 17-18year old students are used to revising so may have better recall
describe the reliability
- high due to standardised procedures which allows replication
- high as supported by Yuille and Cutshall
describe the application
- low as suggests leading qs does not affect recall which could lead to wrong convictions
describe the validity
- low as small sample size
- low ecological validity as carried out in a classroom
- high as control over EVs so there are no distractions, able to establish cause and effect
- low as psychology students so risks demand characteristics
- low task validity
- high as independent measures prevent order effects
- high as objective (percentages not affected by bias)
improvements for future research
- use matched pairs to avoid effects of ppt variables and increases internal validity
- widen sample to non psych students to obtain more representative findings
