With increasing costs of Health Care Delivery Systems, there is a growing need to evaluate the effectiveness of treatment, preventive and promotional health services. While there is considerable concern by programme administrators and evaluation researchers for such assessment, appropriate techniques and methodologies for this purpose have not been well developed. The use of experimental research designs is recommended by many researchers as an ideal mechanism for measuring the attainment of programme objectives. In practice, however, there are few examples of health services evaluation studies where this technique has been applied.

In this paper, the authors outline some of the central issues health services personnel should keep in mind in attempting to apply experimental designs to programme evaluation. Some of the conditions facilitating the use of experimental designs are identified, along with some of the steps that might be taken to improve the application of such methodologies.