There are many difficulties to be overcome when the attempt is made to introduce market research techniques into R&D. It is not only the resistance of technically minded scientists and managements, but the subject matter itself is full of pitfalls. Since it would be most unwise to consider every step in an R&D programme from the point of view of the market it is necessary to divide R&D into several steps in order to decide at which point marketing should exert its influence. This is largely a matter of semantics and solutions are not easy. Nor is it simple to design market research techniques which, when used, will assist managements in deciding which R&D projects to pursue and which not. The material, on which this paper is based, comes largely from the United Kingdom. But the principles involved are world-wide because every industrialised country is faced with the facts of: 1. increasing expenditure on R&D and; 2. the waste of scarce manpower and resources connected with this development.