RESEARCH METHODS
, VARIABLES
Independent variable – the variable that the researcher changes
Dependent variable – the variable that the researcher measures
Operationalisation – clearly defining variables to specifically say how they’ll be
measured
Null hypothesis – a statement that predicts there will be no difference/correlation
Experimental hypothesis – a statement that predicts there will be a
difference/correlation
Non-directional – there will be an effect but not stated which way
Directional – there will be an effect in a particular direction
Extraneous variable – any variable other than the IV that may affect the DV
Confounding variable – any variables other than the IV that may affect the IV and the
DV
Situational variable – stem from aspects of the environment
Solution: standardised instructions and procedures
Participant variables – stem from differences between participants
Solution: randomisation, matched pairs, large representative sample
Demand characteristics – cues from the researcher that suggest that the participants
may have figured out the aim of the study
Social desirability bias – participants change their behaviour to appease the researcher
(to aid or detriment their aim)
Solution: single blind procedure, placebo effect
Investigator effects – stem from the investigator’s behaviour, consciously or
subconsciously
Solution: double blind procedure
, RELIABILITY AND VALIDITY
Reliability
o A measure of consistency
Internal reliability – consistency within items used to measure
External reliability – consistency of the measure over time
Ways to test:
Split half technique – take results from half the participants in one group and compare
with half from another group
Test re-test – participants do the test again
Validity
o The extent to which an observed effect is genuine
Internal validity – the extent to which the results are due to variables being
manipulated and not by extraneous variables
External validity – the extent to which results are true to real life
Ecological validity – the extent to which you can generalise the results to real life due to
the environment
Population validity – the extent to which you can generalise the results to the rest of the
population of other groups
Mundane realism – whether the task itself is true to real life
Ways to test:
Face validity – whether a measure looks like its measuring what the researcher intends
to measure
Concurrent validity – comparing the current method of measuring to a previous one
, VARIABLES
Independent variable – the variable that the researcher changes
Dependent variable – the variable that the researcher measures
Operationalisation – clearly defining variables to specifically say how they’ll be
measured
Null hypothesis – a statement that predicts there will be no difference/correlation
Experimental hypothesis – a statement that predicts there will be a
difference/correlation
Non-directional – there will be an effect but not stated which way
Directional – there will be an effect in a particular direction
Extraneous variable – any variable other than the IV that may affect the DV
Confounding variable – any variables other than the IV that may affect the IV and the
DV
Situational variable – stem from aspects of the environment
Solution: standardised instructions and procedures
Participant variables – stem from differences between participants
Solution: randomisation, matched pairs, large representative sample
Demand characteristics – cues from the researcher that suggest that the participants
may have figured out the aim of the study
Social desirability bias – participants change their behaviour to appease the researcher
(to aid or detriment their aim)
Solution: single blind procedure, placebo effect
Investigator effects – stem from the investigator’s behaviour, consciously or
subconsciously
Solution: double blind procedure
, RELIABILITY AND VALIDITY
Reliability
o A measure of consistency
Internal reliability – consistency within items used to measure
External reliability – consistency of the measure over time
Ways to test:
Split half technique – take results from half the participants in one group and compare
with half from another group
Test re-test – participants do the test again
Validity
o The extent to which an observed effect is genuine
Internal validity – the extent to which the results are due to variables being
manipulated and not by extraneous variables
External validity – the extent to which results are true to real life
Ecological validity – the extent to which you can generalise the results to real life due to
the environment
Population validity – the extent to which you can generalise the results to the rest of the
population of other groups
Mundane realism – whether the task itself is true to real life
Ways to test:
Face validity – whether a measure looks like its measuring what the researcher intends
to measure
Concurrent validity – comparing the current method of measuring to a previous one
