Reflections on goal attainment scaling (GAS): Cautionary notes and proposals for development

Goal attainment scaling (GAS) is a technique for evaluating the success with which services help their clients to attain the personal goals that have been set for them. Evaluators who use the technique construct a five-point scale around each goal that is set for the individual clients who use a service. Clients' outcome levels are converted into standard scores which are scaled to a mean of 50 and a standard deviation of 10. The technique has been in widespread use in education, health and social work in the USA since 1968, but its use elsewhere has been relatively uncommon. This paper suggests that there are problems about the calculation of standard scores in GAS, first, because the statistic is not dealing with interval data, and secondly, because of difficulties in estimating the degree of relationship among the scores of individual clients. However, the paper proposes non-parametric methods of handling the data, and commends the practice of goal-setting and goal-monitoring as a process for developing services.