A four‐disc version of the Tower of London for clinical use

Three studies are reported on the development of a four‐disc version of the T ower of L ondon test of planning ability. The first ( n  = 138) involved the selection of items based on rational and empirical criteria to provide a short test of graded difficulty suitable for use with children and clinical populations. The second study ( n  = 480) checked the properties of the 10‐item test on a new sample and in addition examined the internal consistency and factor structure of the test. The third study ( n  = 61) examined the test – retest reliability of the test over a period of 1 month. The difficulty level of the test remained relatively stable from sample to sample and was sensitive to linear trend in performance from age 5 years up to 30 years. Total score did not reflect the action of a single underlying construct but rather appeared to index a number of factors. Scores were reasonably stable over the 1‐month period studied, at least for the children's sample employed. The four‐disc version is a promising method of assessing planning in children and adolescents in clinical situations.