ABSTRACT
Although modern political scientists began to use statistics extensively only in the 1950s, it was actually political scientists who first developed the field, for statistics originally grew out of the need to keep records for the state. Statistics includes two main activities: statistical inference and statistical measurement. A convenient way to summarize data on two interval-scale variables is to plot all the observations on a scattergram. The measure commonly used to summarize the effect-descriptive characteristics of a scattergram is the regression coefficient. The slope is the regression coefficient, and it is the most valuable part of the equation for most purposes in the social sciences. Any regression line is actually a reflection of the stage that has been reached in developing a theory. The correlation coefficient, r, measures how widely such a body of data spreads around a regression line.
