- Subject index
Validity is the hallmark of quality for educational and psychological measurement. But what does quality mean in this context? And to what, exactly, does the concept of validity apply? These apparently innocuous questions parachute the unwary inquirer into a minefield of tricky ideas. This book guides you through this minefield, investigating how the concept of validity has evolved from the nineteenth century to the present day. Communicating complicated concepts straight forwardly, the authors answer questions like: What does ‘validity’ mean? What does it mean to ‘validate’? How many different kinds of validity are there? When does validation begin and end? Is reliability a part of validity, or distinct from it? This book will be of interest to anyone with a professional or academic interest in evaluating the quality of educational or psychological assessments, measurements and diagnoses.
Chapter 4: The (Re)Unification Of Validity: 1975–1999
The (Re)Unification Of Validity: 1975–1999
This chapter aims to capture the spirit of the period between 1975 and 1999 through an extended discussion of the influence of Samuel Messick, whose ideas on validity increasingly came to dominate the landscape during this phase, ultimately becoming the very zeitgeist of late 20th-century thinking on validity. There are two aspects to this discussion: his triumph and his tribulation.
As we have outlined previously, the classic definition of validity – the degree to which a test measures what it is supposed to measure – presented a unitary conception focused squarely on score meaning. As theorists elaborated this definition, it became more complicated and distinctions began to be drawn, in particular between validity of measurement and validity of prediction (e.g. Cronbach, 1949: 48). With the publication of ...