The outcome of an experiment. Also called the Dependent Variable

The explantory variable is one which is used as a predictor of the response variable. Statistical data analysis wants to reveal the effect of the explantory variable on the response variable. In other words, how are responses influenced by the explanatory variable? For example, one might study how the effectiveness of a remedial mathematics program is influenced by factors such as the length of program, text book, gender, classroom conditions, the characterisics of instructor, and the method of instruction, which are all potential explanatory variables.