The distinction between operational research (OR) and market research is a clear one. The task of operational research is to predict and compare the outcomes of alternative management plans and decisions; the distinctive approach is to develop models which are representations in scientific, possibly mathematical terms, of the relevant factors and relationships of the system being managed. Often, but not always , a model is evaluated on a computer. Initially, such a model throws light on the effect of different management decisions; eventually with progressive refinement, it should predict them with more and more accuracy. On the other hand, the primary task of market research is to collect, summarise and sometimes interpret information about the world external to a marketing company - particularly data about the purchasers and potential purchasers of the company's products. Statistical analyses are sometimes made, but market research reports do not generally include the evaluation of alternative plans to assist the decision-making of management.