The Colour-Form Sorting Test was described by Weigl (1927) as one of a series of investigations into the nature of the psychological deficit resulting from a cerebral lesion. The material consists of 12 pieces: four squares, coloured severally red, yellow, blue and green; four circles, similarly coloured; and four equilateral triangles, similarly coloured (Fig. 1). They are presented in a random arrangement to the patient, who is asked to group them according to any similarity he sees; and when he has sorted them according to one principle, is then asked to sort them according to another.

Other problems involving sorting were presented in Weigl's study, and have been used in a number of investigations, particularly of the effects of frontal lobe lesions. Rylander (1939) found that his group of patients with frontal lesions differed significantly from the normal controls in the number of principles found for grouping 15 objects. Halstead (1940) used 62 common objects, and also found that patients with frontal lesions tended to find fewer principles for sorting than did patients with cerebral lesions located elsewhere. Subsequently Halstead and Settlage (1943) developed a mechanized grouping test, using geometrical figures: three patients, with frontal lesions, and one with a left occipital lesion, made many more errors than did the normal controls; while a patient with a right occipital lobectomy and one with a left parietotemporal lesion performed normally in this respect. Finally Halstead (1947) found that, of his group of ‘indicators” of cerebral damage, a similar test (No. 2) not only differentiated reliably the patients with cerebral lesions from the normal controls, but also gave a significantly higher error score with cases of frontal lesion.

Goldstein and Scheerer (1941) included Weigl's test in their experimental study of abstract and concrete behaviour; and Trist and Trist (1943) and Brody (1943) noted impairment on this test in cases of general paralysis and the presenile dementias.