GLOSSARY
A
a posteriori After the experiment; pairwise comparisons made by the researcher after determining that there is a significant overall F value from ANOVA; also called post hoc.
a priori Determined before, or prior to, an experiment.
adjusted R2 A modified value of R2 in which the degrees of freedom are taken into account, thereby allowing the researcher to determine whether the value of R2 is inflated for a particular multiple regression model.
after-process quality control A type of quality control in which product attributes are measured by inspection after the manufacturing process is completed to determine whether the product is acceptable.
all possible regressions A multiple regression search procedure in which all possible multiple linear regression models are determined from the data using all variables.
alpha (α) The probability of committing a Type I error; also called the level of significance.
alternative hypothesis The hypothesis that complements the null hypothesis; usually it is the hypothesis that the researcher is interested in proving.
analysis of variance (ANOVA) A technique for statistically analyzing the data from a completely randomized design; uses the F test to determine whether there is a significant difference in two or more independent groups.
arithmetic mean The average of a group of numbers.
autocorrelation A problem that arises in regression analysis when the data occur over time and the error terms are correlated; also called serial correlation. ...