validity

• validity = refers to whether a psychological test, observation, experiment produces a result that is legitimate - does it measure what is was supposed to measure, and can it be generalised beyond the research setting within which it was found?
• It is possible for studies and measures to produce reliable data that is not valid. For instance, a broken set of scales may give a consistent reading of someone’s weight which is always 7lbs more than their actual weight. The scales are reliable but the weigh reported is not ‘true’ so the measurement lacks validity.
• Internal validity= refers to whether the effects observed in an experiment are due to the manipulation of the independent variable and not some other factor
• One major threat to the internal validity of a study is if participants respond to demand characteristics and act in a way they think is expected. For example, some commentators have questioned the internal validity of Milgram’s obedience study claiming that participants were ‘playing along’ with the experimental situation and did not really believe they were administering shocks.
• External validity = relates more to factors outside of the investigation, such as generalisation to other settings, other populations of people and other eras
• Ecological validity = the extent to which findings from a research study can be generalised to other settings and situations
• The concept of ecological validity is often misunderstood because people think it is about the naturalness of a study - a more natural setting should mean the findings from the study can be generalised to everyday life. A lab is an artificial setting and therefore people think that the results of lab research should have low ecological validity because people don't behave naturally in a lab. However, if the task used to measure the dependent variable in an experiment is not ‘like everyday life’ this has lower ecological validity.
• Temporal validity = the extent to which findings from a research study can be generalised to other historical times and eras
• Critics have suggested that high rates of conformity in the original Asch experiments were a product of a particularly conformist era in recent American history. Some of Freud’s concepts, such as the idea that females experience penis envy, are deemed to be outdated, sexist and a reflection of the patriarchal Victorian society within which he lived.
• One basic form of validity is face validity, whether a test, scale or measure appears ‘on the face of it’ to measure what it is supposed to measure.
• The concurrent validity if a particular test or scale is demonstrated when the results obtained are very close to, or match, those obtained on another recognised and well-established test. Close agreement between the two sets of data would indicate that the new test has high concurrent validity - and close agreement is indicated if the correlation between the two sets of scores exceeds +80.
• Validity is improved, for example, by using a control group - researcher is better able to assess whether changes in the dependent variable were due to the effect of the independent variable. Experimenters may also standardise procedures to minimise the impact of participant reactivity and investigator effects on the validity of the outcome.
• Many questionnaires and psychological tests incorporate a lie scale within the questions in order to assess the consistency of a respondent’s response and to control for the effects of social desirability bias. Validity may be further enhanced by assuring respondents that all data submitted will remain anonymous.
• Observational research may produce findings that have high ecological validity as there may be minimal intervention by the researcher. This is especially the case if the observer remains undetected, meaning that behaviour is likely to be natural and authentic. In addition, behavioural categories that are too broad, overlapping or ambiguous may have a negative impact on the validity of the data collected.
• Qualitative methods are usually thought of as having higher ecological validity than more quantitative methods of research. This is because the depth and detail associated with case studies and interviews, for instance, is better able to reflect a participant’s reality. However, a researcher may still have to demonstrate the interpretive validity of their conclusions (The extent to which the researcher’s interpretation of events matches that of their participants).
• Validity of qualitative research can be further enhanced through triangulation - the use of a number of different sources as evidence, for example, data compiled through interviews with friends and family, personal diaries, observations, etc.