The Kenya Maize Data Base Project (MDBP) was established in 1992 with the help of the Rockefeller Foundation, the International Maize and Wheat Improvement Center (CIMMYT) and the US Agency for International Development. This book describes in detail the development and application of the MDBP, which uses spatial analysis to integrate data from Geographical Information Systems (GIS) with the results of biological experiments, socioeconomic statistics (including interviews with farmers) and agroclimatic information. This provides a powerful planning tool for targeting new technology to the needs of farmers. The book contains sections on survey methods, ex ante research evaluation and priority setting, and patterns of maize technology diffusion and the impact of research. It concludes with a synthesis of the MDBP results and assessment of future choices. This book is essential reading for maize agronomists, crop modellers, agricultural and development economists, extension workers and planners.