Erratic eye movements and dyslexia: factors determining their relationship.

Studies of dyslexia often produce contradictory results. Studies of eye movement are not an exception to this rule. The differences between Black, et al.'s 1984 and Pavlidis's 1981 eye-movement results are mainly due to differences in: (a) unquantifiable and variable criteria for selection of subjects, (b) incompatible experimental designs and procedures, (c) varying stimulus characteristics, and (d) major differences in the methods of data acquisition and analysis. The solution of these problems requires the establishment of quantifiable Research Diagnostic Criteria for Dyslexia and the use of compatible methods of data acquisition and analysis. The adoption of these standards would lead to a better understanding of dyslexia and would also make possible meaningful replications of major studies.