The Purdue Pegboard Test was first validated against a sample of 80 referred patients independently diagnosed by clinical neurological examination, electroencephalograph, and radiographic procedures. A cross validation sample was subsequently run on 65 consecutive admissions by the same procedures as in the validation sample. A wide variety of acute and chronic disorders including muscular and infectious disease were all represented. Control groups contained patients admitted with lesions either in the peripheral nervous system or below the thoracic spine. (See Appendix B, Table 1-2.)