Validity

What is validity?

The extent to which an observed effect is genuine.

What does internal validity refer to?

Whether the effects observed in an experiment are due to the manipulation of the IV and not some other factor.

What is one major threat to the internal validity of a study?

Demand characteristics.

What does eternal validity refer more to?

Factors outside of the investigation, such as generalising to other settings.

What is ecological validity?

The extent to which findings from a research study can be generalised to other settings and situations.

What is temporal validity?

The extent to which findings from a research study can be generalised to other historical times and eras,

What are two ways of assessing validity?

• Face validity.

• Concurrent validity.

What is face validity?

A form of validity in which a measure is scrutinised to determine whether it appears to measure what it is supposed to measure.

How can face validity be determined?

By simply ‘eyeballing‘ the measuring instrument or by passing it to an expert to check.

What is concurrent validity?

When the results obtained by a particular test or scale is similar to or matches those obtained on another recognised and well-established test.

How can validity be improved in experiments?

• Using a control group.

• Standardising procedures.

• Single/double blind procedures.

How can validity be improved in questionnaires?

• Incorporating lie scales - assesses the consistency of the responses and controls for the effects of social desirability bias.

• Assuring respondents that all data submitted with remain anonymous.

How can validity be improved in observations?

• Use of covert observations - behaviour observed is likely to be natural and authentic.

• Good behaviour categories.

Why are qualitative methods of research usually thought of as having higher ecological validity?

Because the depth and detail associated with case studies and interviews, for instance, is better able to reflect a participant’s reality. This is the extent to which the researcher’s interpretation of events matches that of their participant’s.

How can validity be improved in qualitative research?

• 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.