Research Methods Flashcards
(53 cards)
Hypothesis
prediction!
- Null = no difference
- Directional = positive/ negative change
- Non-directional = no previous research, so states difference but not the way it goes
IV
variable manipulated
DV
variable measured
CV
something other than the IV influencing the DV, varies along with the IV
EV
need to control these, affect the DV, becomes a CV when it varies along with factors interested in
Operationalisation
defining variables
Independent measures design
a separate group of Ps per condition of the study
:) - no order effects, no fatigue
:( - 2x as many people, individual differences
Repeated measures design
the same group of Ps to each condition of study
:) - no individual differences, fewer people, can be counterbalanced
:( - order effects, demand characteristics, fatigue
Matched pairs design
separate groups per condition of study, pairs matched on certain characteristics, like age, gender, IQ
:) - controls order effects, reduces individual differences
:(- takes more time n effect, still a chance of individual differences
Random sampling!
all members of target pop have an equal chance of being selected, like names in a hat
:) - most representative
:( - still not fully representative, time consuming, miss people, some may refuse to take part
Opportunity sample
use Ps available e.g. psychology class
:) - easy, less expensive, less time consuming
:( - very unrepresentative, sample bias
Volunteer sample
adverts. those who reply are in!
:) - reaches target populations
:( - volunteer bias = sample bias, those who want to take part may have similar characteristics
Systematic sample
choose every nth (e.g. every 3rd) member of target POP.
:) - no chance of researcher bias
:( - still possible to be unrepresentative
Stratified sample
use groups representative of target pop e.g. if target pop has 70% males and 30% females use this percentage.
:) - avoids researcher bias, very representative
:( - sample cant reflect all the ways people differ, we are complex and different
Lab experiment
controlled environment, IV manipulated by experimenter
:) - internal validity
:( - artificial, external validity
Field experiment
IV manipulated by experimenter, natural environment
:) - better external validity
:( - poorer internal validity, loss of control, EVs
Natural experiment
where IV naturally occurs
:) - high external validity, allows study of topics that are hard to control
:( - no random allocation = confounding variables , cant be replicated - low reliability
Quasi experiment
contain a naturally occurring IV the researcher examines the effects of on DV in controlled conditions
:) - high internal validity
:( - confounding variables, no random allocation
Primary data
first hand! specific to aim of study BUT harder to obtain
Secondary data
pre-existing, not specific to aim of study
Qualitative data
non- numerical
rich and detailed
harder to compare
Quantitative data
numerical
easy to compare
lacks detail
evaluate measures of central tendency
Median + mode- unaffected by outliers but dont take all scores into account
Mean- looks at all scores, affected by extreme scores
Range
largest- smallest
easy to calculate
influenced by extreme scores
