Measurement of Cognitive Development

Psychometricizing Piaget

The conventional view of the state of play in the 1960s can be summarized by looking to the book Measurement and Piaget and a review of it that appeared in the year following its publication. Measurement and Piaget recorded the proceedings of a Conference on Ordinal Scales of Cognitive Development sponsored by CTB/McGraw-Hill in 1969. In an interesting review of the book devoted to the proceedings of a conference in 1969, Wohlwill summarized rather succinctly what has been regarded as the lack of interest by Piagetians in quantification of [Page 648]cognitive development where the title of the book Measurement and Piaget was juxtaposed against his review title “And Never the Twain Did Meet.” He then painted a picture of the archetypal Piaget deliberately relegating the problems of “psychometricizing” Piagetian measures to a province beyond his concern, on the grounds that Piaget asserted that he had “no interest whatever in the individual.” More tellingly, he then described other developmentalists at the conference as quite ready to let the topic of measurement lie in the limbo to which Le Patron had relegated it.

It would be too easy, as well as erroneous, to disregard Piaget's views on psychological measurement as being ill informed. In his discussion on the role and techniques of psychological research, The Place of the Sciences of Man in the System of Sciences, the critique that Piaget makes of the psychometric techniques of the time shows him to be much better informed than many of his contemporaries. It is only now, after the end of that century, that one might fully comprehend Piaget's prescience: His claim was that the chief difficulty with the sciences of man, and indeed with all of the life sciences, lies in the absence of units of measurement, the property that was common to the measurement systems that abound in the physical sciences. This bold and informed assertion was published in English, after the 1969 measurement conference referred to above, but in print before both the Measurement and Piaget text of 1971 and the “Never the Twain Did Meet” critique of 1972.

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