Alternatives to the value of sales of agricultural products as a major determinant in defining and classifying farms are proposed. Problems in understanding the changing structure of U.S. agriculture in the past 30 years result from: (1) rapid changes in the levels of agricultural prices, (2) the adoption of new technology, and (3) the increased availability and use of off-farm jobs by members of farm operator families. It is suggested that our national statistics classify farms into three major categories: FULL-TIME, PART-TIME, and RESIDENTIAL. A shift away from values of sales as the major classifier of size distributions is encouraged. Labor used in agricultural production and standardized estimated of value added for each acre of crops or livestock unit are proposed to define and classify farms.