Two methodological problems often arising in dyslexia research are considered. The first problem concerns the validity of experimental measures and the related problem of interpreting null results. The second problem involves the effects of sampling from a disabled population if the disorder under investigation has multiple unknown origins.…

Describes a systematic method for producing pictures to accompany textual instructional materials. The resulting instructional design model is then used in an attribute by treatment interaction study of post-secondary school students that was designed to investigate the role of analogical pictures in adult learners' acquisition of higher level…

The two chapters of this monograph deal with the issue of the existence of a perceptual grammar that influences reading proficiency, particularly initial reading proficiency. The first chapter indicates the importance of studying reading and writing in terms of readers' and writers' knowledge of visuo-spatial processing rules. It discusses…