The purpose of this paper is to introduce a new method for fitting item response theory models with the latent population distribution estimated from the data using splines. A spline-based density estimation system provides a flexible alternative to existing procedures that use a normal distribution, or a different functional form, for the…

The purpose of this research project was to compile and analyze data concerning the composition and geographic distribution of South Africa's population for the purpose of future educational planning to meet the needs of four population groups. This document contains statistics and conclusions on: (1) the role of population shifts and…

Information on the number and location of U.S. artists, as reported in the 1980 Census of Population, is examined, and comparisons are made with 1970 Census figures. This document describes national growth trends in specific art occupations and regional changes in comparison to total labor force changes. The impact of migration on the distribution…

The booklet analyzes demographic and economic characteristics of married couples in the United States. The study is based on census data and on information about joint characteristics of husbands and wives. The objective of the study is to revise concepts related to family and household data by adding analysis of wives' characteristics to…