| Noun | 1. | correlation coefficient - a statistic representing how closely two variables co-vary; it can vary from -1 (perfect negative correlation) through 0 (no correlation) to +1 (perfect positive correlation); "what is the correlation between those two variables?" 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 Pearson product-moment correlation coefficient, product-moment correlation coefficient - the most commonly used method of computing a correlation coefficient between variables that are linearly related multiple correlation coefficient - an estimate of the combined influence of two or more variables on the observed (dependent) variable biserial correlation, biserial correlation coefficient - a correlation coefficient in which one variable is many-valued and the other is dichotomous chance-half correlation, split-half correlation - a correlation coefficient calculated between scores on two halves of a test; taken as an indication of the reliability of the test tetrachoric correlation, tetrachoric correlation coefficient - a correlation coefficient computed for two normally distributed variables that are both expressed as a dichotomy |