ABSTRACT
This chapter considers the ways in which outcomes are influenced by methods and point out some of the pitfalls that have dogged clinical and research efforts to study asymmetries scientifically. In any diagnostic or classificatory process, the proportion of cases identified in the sample tested depends on the methods of examination, the type of subject and the criteria of classification. This is as true of laterality as any other variable, whether continuous like height, or apparently discrete like dwarfism. An important handicap to the analysis of the problem of the relations between hand preference and cerebral dominance for speech has been shifts in criterion of sinistrality, between non-aphasics and aphasics, in the clinical descriptions of cases. Clinicians and researchers are likely to note with some interest individuals whose hair parting is on the right as opposed to the typical parting on the left.
