In a study of children’s reading abilities, one group of eig…

In a study of children’s reading abilities, one group of eight-year-olds is exposed to a new program that supposedly enhances literacy. Another group is taught with standard methods for teaching reading. Results of the study indicated that the children taught with the new program learned to read more complex material than did the group who were exposed to the standard teaching methods. In this study, the independent variable was the: