| Noun | 1. | regression coefficient - when the regression line is linear (y = ax + b) the regression coefficient is the constant (a) that represents the rate of change of one variable (y) as a function of changes in the other (x); it is the slope of the regression line statistics - a branch of applied mathematics concerned with the collection and interpretation of quantitative data and the use of probability theory to estimate population parameters parametric statistic - any statistic computed by procedures that assume the data were drawn from a particular distribution linear regression, rectilinear regression - the relation between variables when the regression equation is linear: e.g., y = ax + b |