In many countries where agriculture is the major source of income, great efforts are being made to increase production by improving farming conditions. For this to be successful, development planners must have information about existing farming conditions and about the impact of development activities as they are occurring. Systems of monitoring and evaluation are used to provide this information through data gathering, analysis, and feedback of farm information. With this information project managers can adjust their activities to the farmer's needs and constraints, and planners and policy makers can be kept informed about agricultural change.