IDA encourages and supports interdisciplinary reading The basic cause or causes of developmental dyslexia are not fully understood, and are the major focus of our research. Welcome to the International Dyslexia Association (IDA). IDA’s mission is to actively promote effective teaching approaches and intervention strategies for persons with dyslexia and related disorders. It is an inherited condition, which appears to affect more boys than girls. ChapterValid Assessments for DyslexiaChapterIdenti