The Manufacturing ISM Report On Business is based on data compiled from monthly replies to questions asked of purchasing and supply executives in over 400 industrial companies. Membership of the Business Survey Committee is diversified by Standard Industrial Classification (SIC) category, based on each industry's contribution to Gross Domestic Product (GDP). Twenty industries from various U.S. geographical areas are represented on the committee. Survey responses reflect the change, if any, in the current month compared to the previous month. For each of the indicators measured this report shows the percentage reporting each response, the net difference between the number of responses in the positive economic direction and the negative economic direction and the diffusion index. Responses are raw data and are never changed. The diffusion index includes the percent of positive responses plus one-half of those responding the same (considered positive). All seasonal adjustment factors are supplied by the U.S. Department of Commerce and are subject annually to relatively minor changes when conditions warrant them. The PMI is a composite index based on the seasonally adjusted diffusion indices for five of the indicators with varying weights: New Orders -30%; Production -25%; Employment -20%; Supplier Deliveries -15%; and