Roger D. Barry and Robert A. Carter Northern Michigon University Morquette, Michigon 498%
II
Evaluation of General Chemistry Slide-Audio Tape P i o g r ~ m
During the past five years we have developed a number of instructional systems to assist students in the science major general chemistry course. These materials include a series of 16 mm sound motion picture films outlining the laboratory experiments, slide/tape programs for individual student use relating to treatment of laboratory data for each experiment, similar slide/tape programs covering many of the lecture topics (Table I), and an instructional booklet which contains problem sets covering lecture topics and the outlines of laboratory experiments. The question of effectiveness of these materials in enabling students to learn and comprehend ideas easier needed to be answered. As a first attempt to evaluate the instructional materials, the slide/tape programs were scruteuized. Each of these programs consists of a sequence of 2 X 2-in. color slides (4&80) with the Instructor's comments for each slide recorded on audio tape. Carrels were equipped with a slide projector and a cassette audio tape playback unit (with ear phones) for using these programs. The audio carries the continuity of the study activity by providing verbal instructions for changing slides, for computation pauses, for work sheet drill, and for other relevant activities. When the student comes to the carrel he is given a brief printed outline for use with each program. The outline contains problems and charts discussed in the program and provides students with a work sheet which he rrtains for future study. Students were not required to use
the carrel programs, but during the semester nearly all of the students make use of one or more of the programs. The topical slide/tape programs dealing with logarithms, dimensional analysis, scientific notation, and significant figures are no longer covered in lecture. The class is told that competence in these topics was necessary and they should use the prepared programs to help in learning or reviewing these subjects. Problem sets are assigned for each of these topics to enable the student to test his competence. All students using slide/tape programs are asked to complete an information form which includes student information, the program desired, and the length of time required to complete a particular program. This information was used to evaluate the programs. Initially students were interviewed and those who made use of the lecture and laboratory carrel programs indicated that such an approach was very helpful. Many students asked for o t h ~ rlecture rrlated carrel programs which were not available. Thus, the carrel programs appeared to be useful to the student, but more specific evaluation methods were needed. In order to obtain more information about the usefulness of the slide-audio tape programs, a series of Table 2. Correlation Between Test G r a d e and Time Spent on Carrel Programs"
Grade
Table 1. General Chemistry Lecture Slide-Audio Tape Programs
Program title Significant Figures' Scientific Notation-Using Exponents= Logarithmsr Stoichiometry* Dimensional Analysisa Naming Inorganic Compounds0 Writing Chemical Formular from Namesb Balancing Chemical EquationsMolecular Equationsb Balancing Chemical EquationsIonic Equationsc Balancing Oxidation-Reduction Equations-Line Methodr Balancing Oxidation-Reduction Equations-Ian-Electron Method' Hybridimtion Part 1" Hybridization Part 2 h
Correlation
Test I Test 2 Test 3 Final Exam Laboratory r!,,n*ro
Number of Length of slides tape (min)d
Class size 162 students. Data. significant at 0.14 for 0.01 level. Based on minutessnent in carrel usine - mst.erialsrelated to the test. d Based on total minutesspent in camel during thesemester. B a s e d on total minutes spent on carrel programs relating to the laboratory. (
34 19 44 101 32 53 85
19 18 22 44 16 32 24
27
13
58
25
54
22
58
21
80 79
35 35
Test 1 topic. Test 2 topic. Test 3 topio. At various points the student is instructed to stotJhe tape and try solving a problem or answering a question. T rs tlme is quite variable for different students.
Table 3. Correlation between Test G r a d e and Time Spent on Carrel Programs for Three ACT Groups
Grade
Laboratory Course
Correlationo Correlationb Correlationr (ACT (Less than (ACT 26 2'-25) 22) and above)
0.34 0.19
0.17 0.34
0.33 0.33
=Value of 0.3.5 significant at 0.01 level; 0.27 at 0.0,j level. Group size M students. b Value of 0.33 sienificant at 0.01 level: 0.25 at 0.05 level. Group sise 58 stude2s. Value of 0.35 significant s t 0.01 level; 0.27 at 0.05 level. Group size 50 students. Volume 49, Number 7 , July 7 972
/
495
correlations were made between course success (course grades) and usc of the slide/tape programs (minutes in thc carrel). Tables 2 and 3 detail the correlations. The findings reported in Table 2 show that length of time using the carrel programs can significantly iufluence course grades. Part of the explanation for the observation that minutes in the carrel does not always influence grades might be attributed to the degree of preparedness and overall ability of the students. The data in Table 3 support this premise through correlations for three groups of students, categorized as to compositc ACT scores. (All entering freshman and transfer students are required to take the ACT tests.) Those students with ACT scores below 22 gained most in laboratory, examination, and final course grades. Other groups benefited some, depending on the topics. The material covered in
496
/
Journol of Chemical Education
Test 2 included topics on bonding and structure and use of the carrel programs in this instance helped all ACT groups. Part of the reason for this particular correlation probably is the lack of prior knowledge of the subject matter from a previous chemistry course. These findings are probably underestimates of degree of correlations between grades and minutes in the carrels because the relationships may not be linear. Too, some students required less carrel time than others. However, these results and the time saving factor for instructors and increased flexibility for the student render the continued use of the carrel programs desirable. As additional classes utilize these programs and our experience grows, more detailed evaluations will be possible. We believe it is important to have some continued measure of the success and usefulness of various media as they are applied to courses.
