The Best of Two Worlds A great deal of effort by many teachers has gone into perfecting the Keller plan for instructing and testing chemistry studrnk. Use of the plan in its original form utilizes self study and multiple testing after each chapter or unit of study. 'l'his requires massive grading time. A two-year junior college does not have the benefit of senior or graduate chemistry students who can assist in the grading and individual tutoring program envisioned hy Keller. Another drawback of the original plan is the tendency of students to procrastinate until it is too late to complete the required number of unit tests by the end of the semester. At Del Mar College a modification of the Keller plan has been in use for several years and is pravitlg successful. The students have the benefit of multiple testing and yet the instructor is not overwhelmed by the necessary grading time. A lecture-lahoratory presentation is used. Four 1-hr tests are given during the course of the scmcster a t approximately three-week intervals. These tests cover the material from two or three chapters of the textbook. The students are allowed to take 2 additional tests over the same material duringaset time period (outside the regularly scheduled class or laboratory times) whenever they are not satisfied with their score. Students may repeat the first three tests; the fourth test is given a t the end of the term just before final examination. When students came for a make-up test they draw cards from a test question file. Each question has a number which gives the instrudor the number of the answer from a key. The make-up test is graded as soon as the test is completed with student present. This enables the instructor to assist the student by ex^ plaining mistakes. The test questions are of the cognitive type, and the use of computer grading was rejected because of the desirability of allowine oartial credit far oroblem salvine abilities. Students benefit from the interaction with the instructor durine the
Presented at Southwest Regional Meetmg of the American Chemical Society December 1979.
Patricia H. Suter Del Mar College Corpus Chr~stl.TX 78404
216
Journal of Chemical Education
