Here is one possible attempt:

“Psychometrics” refers to statistical techniques which serve to measure psychological characteristics. Their use has grown in parallel to the use of computers. Researchers who use them are usually interested in individual differences, and they are now used in a wide variety of applied settings such as in schools, job recruitment and career counselling, and in clinical and forensic psychology. According to Kerry Thomas, the creation of ‘increasingly sophisticated psychometric techniques’ has resulted in ‘the development of all kinds of psychological tests and led to a highly profitable industry’. (Thomas, 2002, p293)




Note that the in-text reference for a direct quotation gives a page reference.

At the back of your essay you would put:

Thomas, K. (2002). ‘The individual differences approach to personality’, in Meill, D., Phoenix, A., & Thomas, K. Mapping Psychology, Milton Keynes, The Open University Press.