Dyslexia: Approaches to Validation

Abstract

There is much wisdom in these two essays on dyslexia, by Snowling and by Coltheart and Jackson, as well as a useful and informative summary of many key research findings. Given the fact that debates about the diagnosis and concept of dyslexia have been running for at least the last 40 years (see e.g. Rutter, 1969), and given the immense amount of high-quality empirical research that has been conducted (see e.g. Bryant & Bradley, 1985; Goswami, 1994; Rispens, van Yperen, & Yule, in press), it might be expected that most of the main controversies ought to have been resolved by now. But they have not, as is apparent from the contrasting positions adopted in this forum. It might be hoped that, at least, any well-informed dispassionate reviewer should be able to arbitrate and so decide which view is most valid. Unfortunately, even that is not readily possible. A key problem is that the two papers seem to be starting from different premises and, thereby, tackling a somewhat different issue.