PSYCHOLOGICAL RESEARCH

independent variable

variable that researchers manipulate in order to the effect it has on the dv.

dependent variable

variable that researchers measure to see if it was affected by a change in the IV

extraneous variable

any variable other than the IV that can influence the DV, potentially confounding the results of the study.

confounding variable

an extraneous variable that varies with the independent variable, making it difficult to determine the true effect of the IV on the DV.

controlled variables

variable that researcher holds constant to remove its potential effects on the dv.

aim

a statement outlining the purpose of the research study.

population

the whole group that is of interest to the researcher

sample

smaller, subgroup of the population selected for the research study.

random sampling

ensures that every member of the population has an equal chance of being selected for the sample.

stratified sampling

involves dividing the population into subgroups and randomly selecting samples from each subgroup to ensure representation.

controlled experiments

research method where one or more variables are manipulated to observe the effect on a dependent variable while controlling for extraneous factors.

between subjects design

every member of the sample is randomly allocated to either control of experimental group.

advantage - time efficient

disadvantage - participant differences

within subjects design

each member of the sample is involved in both the control and experimental conditions.

advantages - no individual differences

disadvantage - carry over effects

mixed subjects design

combines both elements of a between and within subjects design

advantage - researchers can test multiple variables

disadvantage - more challenging and complex

conclusions

an overall evaluation and interpretation of the results of the data

generalisations

a decision or judgement about the extent to which the research findings can be applied to the population represented in the sample.