The Screener is intended for people who speak English as a first language, or have at least had their entire education in English medium schools. This is because the screener looks at the discrepancies between ability (verbal and non-verbal) and achievement in reading and spelling, and also at ability versus information processing, including speech sounds. If an individual has limited competence in dealing with written English and understanding of spoken English, they may produce greater discrepancies than did the sample of the general population whom we originally tested with the Screener, and they could therefore appear to have dyslexic tendencies when they don't.