Over the years we have had a number of different types of questionnaires for use in our Dyslexia Questionnaire, which has either been as a standalone, or with other SpLDs. The question is, which is “best”. Of course, there can be no best really, since it comes down to a question of validity, and how can you be sure of the validity of a dyslexia tool when you cannot decide the criteria to know if somebody is dyslexic or not.
I would suggest the main approaches have been:
- Smythe and Everatt 2000 – This has been widely used, including as the default for the British Dyslexia Association. It was originally a survey of the responses to over 50 questions by more than 300 individuals. We used a regression technique to provide weightings to each of the most important questions based on a “self-diagnosis” (i.e. have you been diagnosed as dyslexic?) However, the results were not published in a peer-review paper as we were not able to confirm that those diagnoses were for real.
- Symptom-based checklist – If the major defining characteristics are “a difficulty in the acquisition of reading, writing and spelling”, then all you have to identify (and preferably prove) is that difficulty in the acquisition. (Note that this is not a difficulty, but a difficulty in the acquisition of those skills.)