Results of a study to determine the impact of social policy research upon organizational decisions are reported. Studies of 120 projects in the Netherlands were drawn from three areas of social policy making: industrial and labor relations, regional and urban planning, and social welfare and public health. Three functions of social policy research -- diagnostic, communicative, and cognitive -- are evaluated in terms of policy impact. Results concerning diagnostic functions indicate that the impact of social policy research upon organizational decisions is higher when the research sponsor and research consumer are identical or closely linked; projects accompanied by a steering committee of research team, sponsor, and consumer representatives score higher on policy impact than projects without a steering committee; and projects in which the research introduces, defines, and formulates the problem score higher on impact than those in which the researcher's role is collecting and analyzing information. Communicative functions are concerned with six feedback strategies: design, timing, utilizing various communication channels, manipulating the volume of output, and methods of presenting research results. Findings indicate that using any of the six strategies has a positive effect on the project's impact; social researchers are unaware of the impact of various feedback strategies; and planning strategies at an early state of research enhances the impact of the project. An examination of cognitive functions (publication of research) reveals that research published for a general public has more impact than that published for scholarly journals or not at all. (KC)