POSAC maps the rows (the States) of a matrix in a way that maximizes the preservation of their partial order, with similar States located in close proximity on the map. POSAC is based on the partial order among observations rather than their actual magnitude. POSAC seems to have the same relationship to the principal-component analysis (PCA) as that of the median to the arithmetic mean. In fact, POSAC is a form of original factor analysis. Its advantage over PCA is its robustness to the data. The technique enables observations and variables to be studied simultaneously. Seven index crime categories are analyzed, using the years 1944, 1965, and 1987 to determine changes in crime patterns over time. Figures, tables, and 25 references (Author summary modified)