An exploratory factor analysis of the cognitive functioning of first-year bachelor students with dyslexia.

An increasing number of students with dyslexia register in higher education. As a consequence, information on their pattern of strengths and weaknesses is essential to construct adequate assessment and diagnostic protocols. In a sample of 100 first-year bachelor students with dyslexia and 100 control students, a large pool of cognitive skills were tested using a variety of tests. When we applied an exploratory factor analysis to scores, a model with ten factors fitted the data best. Effect sizes were used to express the processing costs of students with dyslexia. The factors related to reading, spelling, flashed orthography, phonology, naming, math, and reading fluency resulted in large effect sizes. A factor combining all measures for crystallized IQ had a medium effect size. The subtests for fluid intelligence were divided in two separate constructs. Relationships between all subtest scores are visualized and interpreted in a general theoretical and practical framework.