used, the computer can play a valuable role in teaching ... supervised small-group tutorials is probably better in ... consulting the references that are given.
14
mg serum albumin/ml + cycloheximide - cycloheximide 0 min 30 min
3 38
4 37
(1) Why was cycloheximide used? (2) Does the hormone influence the rate of synthesis of albumin? (3) Could cyclic AMP be involved in the mechanisms of action of the hormone? How could this possibility be tested?
Problem 3 A middle-aged man gradually developed symptoms of light-headedness, extreme hunger, lapses of memory and transient paralysis. The symptoms generally occurred before breakfast, disappeared later in the morning and recurred on his way home from work. One day he fell into a coma and was hospitalized the next day, when he had no unusual symptoms. On admission his blood sugar was 5.3 mM but the next morning, after a 15 hour fast it was 2.8 mM. Among other tests was the administration of insul!n, which gave the results shown in the Figure for plasma glucose and C peptide. (a )
Insulin J
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From these results: (1) How does the patient's glucose level respond to insulin? (2) How does the patient's C peptide respond to insulin? (3) What abnormal condition might account for these observations?
BIOCHEMICAL EDUCATION 20(1) 1992
Problem 4 -ACTCATGATGAGAATrCGGATACTCATThe sequence above is part of a gene. It can be inserted into a vector after cleavage by the restriction endonuclease EcoRI. As part of a study on binding of a regulatory factor the T at position 16 of this sequence was replaced by C. As a consequence, the sensitivity to EcoRI was lost. How might the mutant DNA be cleaved for insertion into the vector?
Using Computers to Integrate, Improve Biochemical Education
Consolidate and
B T SEWELL and G R DELPIERRE Biochemistry Department University of Cape Town Rondebosch, South Africa Introduction Recently a prominent American practitioner of computerbased education told an audience of educators how thirteen hours' use of courseware by each of 7000 Californian students had raised their mathematics skills by a mean of one grade level at a cost of $35 per student] While I will not present you with anything quite as dramatic I hope to convince you that if it is appropriately used, the computer can play a valuable role in teaching undergraduates biochemistry. Some eight years ago our introductory biochemistry course was notorious for having the highest second-year failure rate in the University. This forced us to analyze our problems and it stimulated activity on many fronts. Our course, which has a conventional content, is presented in the second year of a three-year science degree. The language of instruction is English. The students entering the course have passed first-year Chemistry and Physics and have at least attempted Mathematics and Biology but that is where the homogeneity ends. The students come from different cultural backgrounds and educational systems and 27% are not native English speakers. At most 30% are Biochemistry majors, the remainder requiring the course as a prerequisite for their studies in other subjects. Even among the Biochemistry majors many are only in the Science Faculty because they were not accepted by the Medical Faculty. This imposes serious motivational problems. An additional problem is that the students majoring in some other subjects are overloaded, being subjected to 20 lectures and four afternoon practical sessions per week. What are the problems with traditional media? About 60% of the students' scheduled time is spent attending lectures. Because of the low level of student
15 participation, information gained during the lecture is rapidly lost unless consolidated by other learning activities. The value of the lecture as the primary medium for those students who have language difficulties is also questionable. Lectures are therefore an inefficient medium from the student's point of view. A system of supervised small-group tutorials is probably better in getting the students to participate but it requires a large number of staff or senior students to act as tutors and a high level of student motivation. We have neither. Feedback from the students is essential in order to ensure that the material presented is being adequately and correctly assimilated by the students. One way of obtaining feedback is by having the students occasionally submit written work. However, the drudgery of marking this work coupled with the long delay between submission and return, diminishes the value of the exercise. In our opinion the most effective spur to learning in the traditional course is the class test. This provides the motivation necessary to study the material at the required level and it ensures that the students participate. Also, if the test answers are reviewed soon after the test the students are optimally receptive to the correct information. Tests also provide the teacher with useful feedback about the quality of the learning process. If only the students were to subject themselves to selfassessment continuously during the course then they could discover their weaknesses and make them up in good time. In normal circumstances, however, the students delay any form of self-assessment until the class tests which in our case are held four or five times per year. This imposes an unhealthy and destructive work pattern in which the students concentrate their efforts on the material to be tested to the detriment of the on-going lectures, further undermining the value of the lectures. Indeed, to be effectively used as a teaching tool, class tests should be short and frequent. However, for various reasons we have never managed to achieve this with traditional teaching. Given the situation described above we decided to turn to computer-based education to solve the problems of shortages of staff, student motivation and quality control. •
Areas of computer application There are three main areas of application of the computer in education: Instruction, Simulation and Testing. The creation of high quality instructional programs is a formidable task. We do not believe that currently available computers and software can rival textbooks as the primary source of instruction in tertiary education. Books are portable, inexpensive and can be enhanced by outstanding graphics. It will be some time and will take the efforts of the major publishing companies before CBE is really competitive in this area. Simulation is an area in which the application of computers seems highly appropriate. In its simplest form a sequence of biochemical events can be simulated for the purpose of explanation and in a more advanced form an
BIOCHEMICAL EDUCATION 20(1) 1992 BE
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entire experimental strategy can be simulated so that a student can make decisions while the computer simulates the consequences of the application of these decisions. This has been done impressively in several areas by the Biochemistry microcomputer group at Leeds University, UK. The third area of application is Testing. Our circumstances are such that this application seemed most appropriate and I will describe our efforts in this area. Testing almost inevitably becomes part of a larger computer-based system in which the students are set tasks and learning objectives by the computer and in which the computer maintains a record of the progress of the students and their test results. Such an approach is referred to as Computer Managed Instruction or CMI. Our contribution to this area is the development and implementation of a management system for a network of PCs. We aim to provide the students with open-book tests which will provide feedback to the students. The questions both set the standard and enable the students to identify their deficiencies which may then be corrected by consulting the references that are given. The question types that can be used exclude those that require the input of graphics or large amounts of text by the student. This however leaves a substantial variety of question types that the computer can mark, and which if skilfully used can test all levels of the cognitive hierarchy, including: (1) Multiple-choice questions; (2) List matching questions; (3) True/False questions; (4) Sentence completion questions; (5) Numerical questions; (6) Questions requiring input of symbols (eg sequences); (7) Questions requiring students to indicate named items in a diagram; (8) Short-answer questions; and (9) Questions requiring the student to indicate the order of a sequence of events (eg a chemical reaction). A problem with computer testing is that the usefulness of the questions in assessing the students' knowledge becomes degraded with exposure. 2 Thus, ultimately the knowledge being assessed is of the quality 'the answer to question 10 is option 3'. Therefore it is necessary to build countermeasures into the tests which include: (1) Drawing a subset of questions from a large question bank; (2) Generating different questions for each student (examples of this include numerical questions and gel or graph interpretation questions); (3) Random ordering of the options of multiple choice questions; and (4) Terminating the test early if the student fails a number o f questions.
The problem of management In order to present the tests to the students they must be organized within an accessible and logical framework. There must also be reporting tools so that the instructors can assess the progress of both of the class as a whole and individual students. The subject matter is arranged in a hierarchy of Curriculum, Course, Topic, Objective and Question. The student works towards mastery of objectives which is judged by his or her ability to answer a set
16 number of questions. Once all objectives within a topic have been mastered the topic is said to be mastered and so on up the hierarchy. We allow the students to work on any objective at any time. We have designed and coded software called 'The Manager' in order to manage this structure by setting up class lists and curricula, present the structure to the students and report their progress. Another feature of 'The Manager' is its ability to act as a communications interface between the students and the instructors. It is important that the extended use of computers in education does not degenerate into an impersonal exercise to the detriment of face-to-face contact between the student and instructor. We feel that providing this additional channel of communication has increased the frequency, and improved the quality of communication between the students and instructors.
The multi pass strategy Having put in place the infrastructure for computer-based education it became important to re-evaluate the role of the conventional presentation methods. Our aim is to make optimal use of each resource while fostering the students' self reliance. The strategy involves multiple passes through each block of material, each pass having a specific goal, namely, (1) Motivation-stimulation; (2) Guided self-study; (3) Practice exercises; (4) Self evaluation; and (5) External assessment. Motivation and stimulation are achieved by means of overview lectures at strategic points in course. At the beginning of the course the students are given a study guide detailing reading, laboratory work, computer tests, etc, that they are expected to complete during the course. They are also given a set of target dates for the completion of each separate objective. Practice exercises which can be monitored are provided by means of the computer tests. When a student has sufficient confidence he or she may try a synoptic test covering the whole course. This test may be taken only once and its purpose is to give the student the confidence to face external evaluation. Class tests As the ratio of computers to students is about one to eight it is not possible for all the students to sit a computerbased class test at once. We therefore resorted to optical mark reader technology. This restricts the question types to the variants of multiple-choice. However we do not believe this to be disadvantageous, especially since the purpose of the test is more of an early warning than a final assessment. The optical mark reader is linked to the computer system and the test marks are reported by 'The Manager' along with the rest of the students' results.
The integration of practicals We also have integrated certain laboratory practicals into the management sytem. In this case there are two facets to the exercise: testing of the students' knowledge of the theoretical background, which can be done within the above framework, and assessing the quality of execution B I O C H E M I C A L EDUCATION 20(1) 1992
of the experimental work. Many laboratory practicals can be structured around the determination of unknowns which could be quantitative such as concentration or rate, or qualitative such as composition. In such cases the administration of the exercise is a simple extension of our philosophy. The system can assign sample numbers to the students at random, the students then perform their analyses and return to the computers for verification. We have found that this approach is extremely successful with some students, stimulating them to repeat the analyses several times in the afternoon in an effort to get it right. Of course, there are instructors on hand in the laboratories to give guidance where necessary.
Acceptance of the medium by staff and students The system in its present form has been used by the second year Biochemistry class for the last three years, involving about eighty students per year. The attitude of the students who actually use the system is overwhelmingly positive. More than half the students log in regularly and master most of the tests. Notwithstanding this there is always a sizeable proportion of the class who do not use the system adequately including one or two who are overtly hostile. We have not applied punitive measures against those that do not complete this component of the course and threats to do so have not persuaded non-users to change their habits. When asked why they do not use the system the majority responded that they do not have the time. It is interesting to note that no student reported any difficulty in using the computers or that the mechanics of using the computers impeded the learning process. For most students, using the computers was a positive experience and better than they thought it would be. Most felt that their knowledge of the subject matter had increased as a result of using the computers and indeed this is substantiated by a comparison of the results of users and non-users from the same class. The average mark in the final examination for those who use the system adequately is 7% higher than for those who do not. This is clearly sufficient to justify our effort. Most students would not like a reduction in the number of lectures as a result of having access to the various computer based activities and clearly separate in their minds the activities of learning and being tested. This point of view is at variance with our own and possibly results from preconceived expectations which are fulfilled by their experience of traditional school and university education. Attempts at reducing the number of lectures had interesting and unforeseen consequences. The students became dissatisfied and complained, their parents phoned in and colleagues raised their eyebrows. It appears that the daily lecture has some hallowed status. The students expect it and believe that it is what they are paying for. The university expects it and believes that it is paying the staff to deliver lectures. The staff in the Biochemistry Department have, with notable exceptions been reluctant to embrace CBE as an
17 adjunct to their use of traditional methods. The response has varied from enthusiasm to apathy to highly negative attitudes. This causes considerable problems for the project. Students who are exhorted to use the system by some lecturers and actively discouraged by others are more likely to become confused and reject the medium than use it to its full advantage. One could speculate why attitudes vary to such a marked degree. It is fair to say that most universities with a first-world orientation are not noted for the use of innovative instructional technologies. The teaching staff tend to be appointed for their research potential and promoted on their research record. There is little incentive to move beyond the traditional teaching methods particularly when this type of adventure is not only extremely time-consuming but may also lead to disturbing discoveries about one's preconceived notions and daily pedagogical practices. This attitude must be contrasted with that in commerce and industry which have been quick to seize the benefits of computer technology in order to assist and enhance their own training processes, possibly because they value results above tradition. One can only hope that university practitioners of CBE will succeed in gradually eroding the resistance to much needed change in outmoded and questionable pedagogical practices. We continue to believe that the promise of the computer as an educational medium is considerable. The positive responses of almost all the students that have used our system have encouraged us to continue development and we ultimately hope to develop tests covering the entire syllabus of a conventional biochemistry course.
Biochemistry Textbooks for Effective Learning F VELLA
University of Saskatchewan College of Medicine Department of Biochemistry Saskatoon, Canada S7N OWO
Introduction This paper is intended to describe the theoretical characteristics of a textbook of biochemistry that is based on sound educational principles, and that would therefore be more likely to lead to effective learning. It will explore the subject from the perspective of the three components of the title, ie, Biochemistry, Learner and Textbook. The dynamic nature of these components is represented in Figure 1, which also includes the Teacher although his or her role will not be considered here. After a brief description of what I mean by each of these components, I shall try to apply this to a description of an ideal textbook that addresses each of them. BIOCHEMISTRY (subject to be learned)
II
e f f e c t i v e learning) TEXTBOOK (medium or tool for learning)
TEACHER
Acknowledgement We thank the University of Cape Town and the Claude Harris Leon Foundation for funding the development of 'The Manager' and Biochemistry Courseware. BTS thanks the University of Cape Town and the Mauerberger Foundation Fund for sponsoring his trip to Jerusalem to present this paper.
'EARNER (person to achieve
(guide to, f a c i l i t a t o r of, learning)
Figure 1 Biochemistry, textbook and learner
Biochemistry References 1Gaede, O F (1991) 'Avoiding Brownian Motion: The Need for National Leadership in CBT/CBE' Second Conference on Computer-based Education and Training, University of South Africa, Pretoria, 26-27 February 2Deipierre, G R (1991) 'The Degradation of Higher Levels of the Cognitive Domain and its Implication for the Design of Computerbased Question Episodes', Studies in Higher Education 16, 63-71
It is important to define what is meant by Biochemistry. Different persons will have definitions which may differ in detail. My definition is as follows:
Biochemistry is a body of knowledge compiled through experimentation; it has a past, a present, and a future; it makes use of a broad range of laboratory techniques; it is a scientific approach for the construction of physico-chemical knowledge and understanding of living systems; it is the basis of all biological science; it is a dynamic thought collective with an evergrowing and changing language, concepts, principles, method and thought style. The reader will note that in an attempt to represent my understanding of biochemistry, I had to resort to a very complex description. A textbook author's personal description of biochemistry will determine the structure, content and overall tone of the book he or she produces. The narrower the description the narrower the textbook's approach and presentation and therefore the image that
BIOCHEMICAL EDUCATION 20(1) 1992
