ABSTRACT
This chapter discusses one of Desmond Nuttall's classic contributions to furthering the conceptualization of educational assessment. Arising out of work Nuttall's was asked to do by the Manpower Services Commission, the paper was published in the European Journal of the Psychology of Education. The paper reviews the concept of validity, and adopts the formulation that validity is the extent to which the results of an assessment can be generalized. The evidence about the validity of paper-and-pencil tests is then examined, leading to the conclusion that the relationship between performance on such tests and criteria of occupational performance is generally very modest. In conclusion, the responsibility of the assessor to elicit the candidate's best performance is contrasted with the responsibility to ensure the validity of the results of the assessment, and hence to ensure that the sample of behaviour assessed is representative of the universe of interest.
