Validity
Validity Definition:
Extent to which an observed effect is genuine – if it measures what it is
supposed to (internal validity) or if it can be generalised beyond the research
setting (external validity)
Internal Validity
Measures what it is supposed to
Whether effects observed are due to manipulation of IV and not other factor
Major threat to internal validity is if P’s respond to demand characteristics
(act in a way they think is expected of them)
External Validity
Relates to factors outside of investigation
Ecological – can generalise to other settings, particularly ‘everyday life’
Temporal – extent to which findings can be generalised to other historical
times and eras
Population – can you generalise to other people
Ways of Assessing Validity:
1. Face Validity
- basic form of validity
- does it measure what it is supposed to
- can be done simply by ‘eyeballing’ the measure or giving it for an expert to
check
2. Concurrent Validity
Validity Definition:
Extent to which an observed effect is genuine – if it measures what it is
supposed to (internal validity) or if it can be generalised beyond the research
setting (external validity)
Internal Validity
Measures what it is supposed to
Whether effects observed are due to manipulation of IV and not other factor
Major threat to internal validity is if P’s respond to demand characteristics
(act in a way they think is expected of them)
External Validity
Relates to factors outside of investigation
Ecological – can generalise to other settings, particularly ‘everyday life’
Temporal – extent to which findings can be generalised to other historical
times and eras
Population – can you generalise to other people
Ways of Assessing Validity:
1. Face Validity
- basic form of validity
- does it measure what it is supposed to
- can be done simply by ‘eyeballing’ the measure or giving it for an expert to
check
2. Concurrent Validity
