In answer to the need for more effective punctuation instruction, a project, based on the theory that an essential relationship exists between intonation and punctuation, was designed for and executed with two 9th-grade student groups--one experimental, the other control. The experimental group received punctuation instruction through the use of taped lessons and corresponding programed exercises, while the control group received no instruction in punctuation. Three types of tests, two objective tests and a written paragraph, were prepared, and all three were administered as pre-tests, post-tests, and retention tests. Although the results showed no significant improvement in the use of end marks, the experimental group demonstrated significant improvement in comma use to set off non-identifying modifiers and within a series. Both groups of students performed the same on the two types of objectives tests, indicating that test design did not influence the results. (Data analysis and tables of findings are included, as well as appendices containing a student booklet, supplementary exercises, tests, raw scores, and samples of student writing.) (JM)