research methods Flashcards
IV
variable that is manipulated
DV
variable that is measured
extraneous variable
interferes with the relationship of IV and DV. if not controlled a cause-and-effect relationship cannot be established.
confounding variables
EV’s that are not controlled and therefore affect the results (can’t be sure the change in DV was due to the IV).
null hypothesis
states that any difference or relationship is due to chance.
e.g. there will be no difference in recall between groups that learn and recall words out of twenty in the same environment to those who recall in a different environment. any difference will be due to chance.
one tailed/directional hypothesis
states the direction that your story will go in. e.g. more words out of twenty will be recalled when recall happens in the same environment compared to a different environment.
two tailed non-directional hypothesis
states a difference but doesn’t say what way it will go. e.g. there will be a significant difference in the amount of words recalled out of twenty depending on whether they’re recalled in the same or different environment.
independent measures
when you use different ppts in each condition. two groups.
repeated measures
involves using the same participants for each condition.
matched pairs
invites being different but similar participants n each condition. an effort is made to match the participants in each condition based off important characteristics.
order effects
if you do a task twice you’re likely to experience boredom, fatigue or to be better at the task.
counterbalancing
can be used to minimise order effects. participant sample is divided in half, first half do condition A followed by condition B and the second half do condition B followed by condition A. any order effects should be balanced with this technique. ABBA.
individual differences/participant variables
these are differences between participants that may affect results, e.g. tolerance to substances, personality, etc.
random allocation
means all participants should have an equal chance of taking part in each condition, will avoid bias when experiment is carried out and limits effects of participant variables.
situational variables
environmental factors that may affect results, e.g. wind, rain, etc.
experimenter effects
cues may be given by the researcher (whether it be purposely or not) that may affect results, e.g. tone of voice, gestures, etc.
experimenter bias
previous bias the researcher has, could be on what’s being studied or the participants (could be on purpose or subconscious)
single blind
participants are unaware of the aim so they don’t change how they perform (helps control demand characteristics)
double blind
neither the researcher or participant know the aim of the study (helps control demand characteristics and experimenter bias)
random sampling
participants are selected by chance. in theory everyone in target population should have an equal chance of being selected.
opportunity sampling
the researcher asks who is available at the time of the study, tends to be less representative.
stratified sampling
participants are selected from different subgroups, often done by identifying target population and randomly selecting a representative amount. representative.
volunteer sampling
participants volunteer to be in research, may respond to an advert, etc. less representative.
case studies (AO1)
- a case study is an in-depth investigation of an individual or group
- uses triangulation to gather data in multiple ways (qual and quant)
- behaviours are studied after the event that may have caused them has taken place
- case studies are longitudinal meaning that they are done over a long period of time to observe changed in behaviour
- case studies can be nomothetic if there re unexpected results which leads to further research that can be applied to everyone
- usually done in a naturalistic setting
why do we study brain damaged patients?
- allows us to treat and rehabilitate patients
- allows us to see how cognitions are affected
- we can gain more insight into what areas of the brain are responsible for what behaviours/types of memory
evaluation of case studies - strengths
- case studies allow for detailed, in depth data to be collected as they are longitudinal. therefore, psychologists can see changed in behaviour which may help them to find more suitable treatments
- case studies have good validity as they construct a ‘case history’ of the client which usually involves a number of different research methods. this use of triangulation increases internal validity as it means that conclusions made are more accurate and in depth
evaluation of case studies - weaknesses
- a weakness is that it is hard to generalise findings as case studies are usually unique to individuals (or a small group) and there are individual differences in behaviours and different types of brain damage. therefore, results can’t be applied to a wider population
- case studies lack validity as they gather qualitative data, which is subjective. therefore, results may be less accurate as bias can occur
HM (AO1)
- when HM was 7 he fell off his bike and was left unconscious for 5 mins
- HM started having seizures from the age of 10 and when he got 16 they got a lot more severe
- HM underwent a surgery at age 27 in which his hippocampus (which is responsible for encoding STM into LTM) was removed through bilateral medial temporal lobe resection
- HM had anterograde amnesia (couldn’t form new memories) and also struggled with his episodic LTM specifically following his surgery
- HM’s procedural memory remained intact and his personality didn’t change, IQ went from 104 pre-op to 112 post-op
- triangulation was used to study HM
- HM was studied over a period of 50 years
HM evaluation - strengths
- there is high generalisability as everyone’s brain and it’s properties are the same, therefore the findings of HM can be generalised to the wider population
- there is high reliability as triangulation was used to gather data, e.g. MRI scans and IQ tests were used which are objective, therefore results can easily be checked for consistency
- there is high validity as HM was a longitudinal study meaning that results are more in depth and entailed, therefore the results are more accurate
HM evaluation - weaknesses
- there is low generalisability as the case study is unique and specific to HM and his brain damage, therefore results aren’t representative of the wider population/others with brain damage
- there is low ethics as it could be said that HM didn’t have the capacity to give fully informed consent, therefore ethical guidelines have not been followed
- there is low internal validity as qualitative data was gathered which may be bias, therefore results are less accurate
HM application to society
- if results are nomothetic then the study may be further researched and therefore may be applicable to the wider population. there is high application as it shows the difference between safe and unsafe surgery and the consequences
