ABSTRACT
This chapter introduces statistical techniques for measuring the strength of relationships. The correlation coefficient, r, and measures how widely such a body of data spreads around a regression line. This coefficient compares a set of data with ideal models of a perfect relationship and a perfect lack of relationship, and assigns to the relationship a score ranging in absolute value from 0 to 1. The numerical measure summarizes the effect-descriptive characteristics of a scattergram is the regression coefficient. The strength of a relationship measured using either correlation or regression analysis. The chapter reviews relationship between variables bound up with the extent to measure the variables validly. Random measurement error distorts the relationship between variables. The relationship between the two variables increases from left to right, as it appears under conditions of increasing levels of random measurement error. The researcher uses census tract data on a large city, correlating percent black with percent voting and percent male with percent voting.
