Validity refers to the extent to which an indicator (or set of indicators) really measure the concept under investigation. This post outlines five ways in which sociologists and psychologists might determine how valid their indicators are: face validity, concurrent validity, convergent validity, construct validity, and predictive validity.
As with many things in sociology, it makes sense to start with an example to illustrate the general meaning of the concept of validity:
When universities question whether or not BTECs really provide a measure of academic intelligence, they are questioning the validity of BTECs to accurately measure the concept of ‘academic intelligence’.
When academics question the validity of BTECs in this way, they might be suspicious that that BTECs are actually measuring something other than a student’s academic intelligence; rather BTECs might instead actually be measuring a student’s ability to cut and paste and modify just enough to avoid being caught out by plagiarism software.
If this is the case, then we can say that BTECs are not a valid measurement of a student’s academic intelligence.
How can sociologists assess the validity of measures and indicators?
There are number of ways testing measurement validity in social research:
- Face validity – on the face of it, does the measure fit the concept? Face validity is simply achieved by asking others with experience in the field whether they think the measure seems to be measuring the concept. This is essentially an intuitive process.
- Concurrent validity – to establish the concurrent validity of a measure, the researchers simply compare the results of one measure to another which is known to be valid (known as a ‘criterion measure). For example with gamblers, betting accounts give us a valid indication of how much they actually win or lose, but wording of questions designed to measure ‘how much they win or lose in a given period’ can yield vastly different results. Some questions provide results which are closer to the hard-financial statistics, and these can be said to have the highest degree of concurrent validity.
- Predictive validity – here a researcher uses a future criterion measure to assess the validity of existing measures. For example we might assess the validity of BTECs as measurement of academic intelligence by looking at how well BTEC students do at university compared to A-level students with equivalent grades.
- Construct validity – here the researcher is encouraged to deduce hypotheses from a theory that is relevant to the concept. However, there are problems with this approach as the theory and the process of deduction might be misguided!
- Convergent validity – here the researcher compares her measures to measures of the same concept developed through other methods. Probably the most obvious example of this is the British Crime Survey as a test of the ‘validity’ of Police Crime Statistics’. The BCS shows us that different crimes, as measured by PCR have different levels of construct validity – Vehicle Theft is relatively high, vandalism is relatively low, for example.
Bryman (2016) Social Research Methods