ABSTRACT
I have long thought that psychologists tend to pay too little attention to distinctions such as that between defining (what we mean by) something and understanding it (seeing/saying how it works, what goes on), or between either of these and assessing (how you tell) when something is present. Ignoring such distinctions can be problematic enough in what used to be called ‘pure’ psychology, where psychologists are selecting their own topic of interest and working within a well-established theoretical tradition. But in applied areas such as education it has often tended to be misleading and counter-productive, since here not only does the field decide the priorities for the applied psychologist to elucidate, but often has no clear and agreed meaning for the terms it uses. When ‘operational definitions’ are introduced in lieu of theoretical conceptualisation, then we all know the consequences.
