A New Area Sampling Frame and Its Uses

Abstract

A REA sampling for agriculture's uses in the United States has been identified with the master sample materials prepared at Iowa State University in the early 1940's. The area method of sampling involves subdividing the entire area to be sampled in each state into sampling Sampling based on the master sample frame refers to the use of areas of land as sampling In the preparation of this frame, three types of land areas were identified based on incorporation and density of population. The county highway maps were used for this purpose. Thus, three strata, (1) open country, (2) urban places, and (3) rural places, were identified in the sampling material. Also, the open country was divided into units which were called units. The word was used to convey the fact that a count of farms and dwellings on the maps was made for each unit. For each count unit, a number of sampling units, or segments, was assigned, based on the farm count. While these three strata plus geographic stratification were adequate for the relatively homogeneous agriculture of the early 1940's because of the general or diversified nature of the family farm, rapid changes have occurred which make the degree of stratification inadequate, especially in the western states. This inadequacy was recognized early by the designers of the master sample materials and efforts were started in the late 1940's to stratify those states west of the 100th meridian. However, this project was never completed because of diversified interests and lack of funds.