Stemhen K. Lower Simon Fraser University Burnaby 2, B.c., Canada
1
Audio-Tutorial amd CAI Aids For problem solving in introductory chemistry
Problem solving has long been recognized as an essential part of any course of study intended to convey more than a qualitative and superficial view of chemistry to the beginning student. The role of the numerical problem in the introductory course is presumably to develop the student's understanding and use of chemical principles, with the view of increasing the meaning and utility of chemistry to him, both as a practical tool and as an intellectual adventure. Whenever a given principle is successfully applied to a problem, some degree of reinforcement of the principle itself is achieved, and its scope and limitations become more clearly delineated. If problem solving is to lead to such a goal, two p r e conditions must be met by the student: He must have a reasonable degree of acquaintance with the principles themselves, and he must be able to analyze the problem in terms of these principles and follow through with the correct logical and arithmetical operations. I t is this second facility-sometimes called analytical skillthat is so evidently lacking in many beginning students. Although the extent to which this skill can be developed in students of normal intelligence and motivation still seems to he an open question in educational circles, it is clear that it will not be enhanced if the student is initially so deficient that he is unable to exercise it in successful problem solving. Furthermore, the entire value of the problem set as an educational tool can he lost if the student is continually hogged down in problem solving; his attention tends to remain narrowed down to the mechanistics of the problem, and the problems themselves tend to be viewed as the principal subject matter of the course, if not of the science of chemistry itself. These difficulties are generally recognized, as evidenced by the attempts of most freshman-level courses to provide special help to students in connection with their numerical problems work. One approach that is widely used is to supplement the ordinary lecture sessions with small tutorial classes known variously as "recitation," "quiz," or "help" sections. While the value of these groups can he considerable, there are several disadvantages in employing them primarily for this purpose. First, each student has his own particular stumbling block, which requires more or less individual treatment. Although a good instructor will attempt to generalize his remarks so as to hold the attention of the remainder of the class, he rarely achieves complete success in this, and in a sense the entire class comes to a halt while each student's difficulties are resolved. By the time several such student-teacher dialogues have
taken place, the other members of the class are bored and the brighter students may well feel (with some justification) that their time is being wasted. More importantly, the slower student is faced with two unhappy alternatives-he can either publicly admit that he is stumped, or he can remain silent in the hope that someone else will ask the "right" question; after several such sessions, all too many of these student,^ choose the second alternative, if they still bother to attend at all. Another difficultv in using the scheduled class as a "help" session is simply the arbitrariness of the scheduled meeting time, in relation to the student's own schedule of activities. Problem solving should represent a nearly total involvement by the student, presupposing a certain emotional state on his part, as well as the usually cited factors of physical comfort, freedom from distractions, etc. He should be able to get his help when he needs it, or at least within a flexible time schedule. The Audio-Tutorial Several years ago we commenced experimenting wit,h tape-recorded commentaries on the problem sets with a view to furnishing the student with more flexibly scheduled and individual help. This activity, which commenced as an outgrowth of the extensive use of audiotapes in our booth-type freshman laboratory', has met with enthusiastic acceptance by the students and has undergone considerable refinement. The purpose of the audiotape is not to "work the problem" for the student, hut to clarify the problem and fit it into the context of the other material of the course. Considerable stress is placed on pointing out those chemical principles that relate to each part of the prohlem, and the way is shown to the proper approach to the solution, always leaving the student enough to do on his own to keep him from merely taking dictation and copying the solution from the tape. There is frequently a very fine line between "giving the problem away" and being too ambiguous to help the student who is really having trouble. We have lately found it helpful to prepare several sheets of printed supplementary material to accompany the study tapes (Fig. 1). Each sheet is divided into "frames" to which reference is made at the appropriate location on the tape. This greatly facilitates the presentation of equations, graphs, and other expressions that must he visualized in order to he discussed. 1 FLITCROFT, N., WONG,E., ada, 19 (9), 47 (Sept., 1967).
AND
PATE,B., Chemistry in Can-
Volume 47, Number 2, February 1970 / 143
blocks os he proceeds, wing the recorded materiol 01 o guide. This sheet, together with any other notes the rtudent may hove, is then "red to prepore the materiol that is eventually honded in for making.
I t is especially beneficial to have the student fill in partially completed expressions on the printed sheet as he goes along. This serves to discourage the student's tendency to lapse into a passive mode as a casual listener. Although earlier tapes were made extemporaneously, we find the presentation is much improved by writing a script beforehand; this permits tighter control over the structure of the commentary and is particularly important if much reference is made to the printed material. The most successful tapes seem to be those spoken in a normal conversational manner, but with sufficient pauses to give the student a chance to think. The pauses also serve as breaks at which he can stop to work on the problem or back up and hear a given portion again. Although we have found that students will tolerate a more amateurish spoken commentary from their own lecturer than from a person who is completely unknown to them, we strive for as perfect a tape as possible and edit the master tapes heavily, replacing all slurred or mispronounced words, extraneous sounds and awkward pauses. The tapes are usually made available approximately half-way between the time the problem set is issued and the day it is due. This encourages students to commence their work on the problem without depending on the tapes, in the hope that the necessary reading and study will make recourse to the tape unnecessary or at least increase the meaningfulness of the tape to the student if he must use it. The fact that more time is generally required to work a problem with the full aid of the tape than without it tends to encourage students to do as much as possible on their own.
liminary experience is that CAI affords two significant advantages over audiotapes: the opportunity for branching, and the possibility of controlling the student's progress by requiring him to work the problem completely and in an orderly fashion. This is particularly important when the program covers assigned problem material, and means that a student can be made to demonstrate his understanding of the relevant principles in order to complete the problem. The amount and diversity of branching is limited only by the time and imagination of the instructor who writes the program, and serves to tailor the program to the individual student. The more capable students, who will often have completed the problem and may only seek confirmation that they are on the right track, can run through the program in a few minutes, while the slower student will be stopped and given whatever supplementary material is required, and then be tested on his understanding of the material before proceeding. In a CAI system provided with typewriter terminals, the student is also furnished with a printed record of his encounter with the computer that he can consult for future review (Fig. 2 and 3). We have not yet begun to use many of the CAI features now available, such as computer-controlled andiotape and slide presentations, video terminals, student testing functions, and the capability of the system to collect data on the frequency of selected kinds of student errors. Another aspect of CAI that is of intense local interest is the prospect of sharing our computer and programs with junior colleges and high schools, particularly
Computer Assisted Instruction
We are just now commencing to explore the applicability of CAIa as a problem-tutorial tool. Our pre"ost of the present literature on CAI seems to be divided between highly specialized research papers in the educations1 psychology field, and brief general articles in teachers' journals and the popular press. Probably the most readable and comprehensive survey of the scope and application of CAI will be found in STOLUROW, LAWRENCE M., "Computer Assisted Iustruction," 1968, published in the Education Automation Monograph Series by American Data Procgsing, Inc., 19802 Mack Avenue, Detroit, Michigan 48236. A number of interesting articles appeared in Datamation, 14 (9) ppg. 2 2 4 7 (Sept. 1968). Other useful articles are SUPPES, P., Phi Della Kappan, 69,420-29 (1968) (implications of CAI on the future of education) and T. F. AudimiSual Instruction 11, 2 2 3 (1966) (deHARTMAN, scription of the general features of the IBM Coursewriter Language).
144
/
Journol of Chemical
Education
Figure 2. Block diagram ond Row chort for o CAI program on a bomb calorimetry problem. Each rhoded block reprerenh a "label" or discrete section of the progrom identifled by the number in the upper right hond corner. Eoch lobel may contoin m y number of questions, stoternenh, ond logic operations. A student whose wrong-answer I"wa"1 responses and requirements for remedial work can b e met without branching will proceed through the vertical sequence of lobelr indicated by the heavy arrows on the right. Other students will be branched so os to follow different pothways through the progrom; branching may occur autom~licollyafter o wrong onrwer, after a series of unruccertful attempt$ at an answer, or a t the student's request. Mothemotical operations themrelver ore performed b y the student.
1-
I
r r r s t , ,Cat I,
7 e.,,, w. 8 =act, 12, 9 .a I* 1- I0 t. .I
I*.,ma,
nm-r
+ .-I"
"I, . u r . l " a ,
,a.
or-l.n*r
11.
,-
1- 11 t11l.111 1- ,I
"0,"
I. 1, t" e.,.I
n,.
rdd.... .,,,I
I. Ill .l,.l Xa
