Validity

• Validity is the legitimacy of a method or finding and the extent to which the experiment has measured or can measure what it sets out to
• Internal Validity is whether the effects observed in a experiment are due to manipulation of independent variable and not another factor
• External validity focuses on factors outside of the experiment e.g. setting, population
• Population validity is the extent to which the findings can be generalised to the wider population
• Ecological validity is the extent to which findings can be generalised to other settings/situations
• Temporal validity is the extent to which findings can be generalised to other times/eras e.g. Freud in the Victorian era
• Validity can be assessed using face validity or concurrent validity
• Face validity is where a measure is scrutinised to determine whether it appears to measure what its supposed to - by either 'eyeballing' the measuring instrument or passing it to an expert
• Concurrent validity is the extent to which a psychological measure relates to an existing similar measure using a recognised or well-established test
• High concurrence is considered above 0.80
• In experiments validity can be improved by using a control group and standardised procedure to determine the effect of the IV, and single r double blind trials to reduce demand characteristics and researcher bias
• In questionaires validity can be improved by incorporating a lie scale to control effects of social desirability bias, and to keep results anyonymous
• In observations validity can be improved by ensuring behavioural categories are not ambiguous and do not overlap
• In qualitative research validity can be improved by demonstrating interpretive validity through coherence of researcher's narrative, triangulation
• Predicitive validity is where scores on a test are used to predict future behaviour by correlating with some criteria you would expect it to predict
• Interpretive validity is the extent to which the researcher's narrative matches that of their participants