The use of computers as an instructional aid is widely advocated as a means to capture the attention of the current computer literate generation of students. A study was designed to assess the effectiveness of using computers as a supplement to the standard mode of instruction. Forty students in an alternative school were randomly assigned to one of four methods of teaching basic math skills. The four methods were lectures only (L), lectures with remedial text book assistance (L/R), lectures with computer assistance (L/C), and computer instruction only (C). After a 10-week instructional period, an exam evaluating basic math skills was taken by the students. The difference in the scores on this exam and on an exam given just prior to the 10-week instructional period for each student is given in the following table. A few of the students did not complete the program, thus producing an unequal number of students in the four modes of instruction.

The researchers want to determine which method of instruction produces the largest increase in test scores.