THE EFFECTIVENESS OF THE LECTURE

Gabriel Virella, M.D., Ph.D.

Department of Microbiology and Immunology

Medical University of South Carolina
Charleston, SC 29425

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The recent ACME-TRI Report (1) notes that the response of most medical schools to the GPEP report recommendation to reduce the number of lecture hours by one third or one half (2) has been disappointing. In general the decrease in lecture hours has been modest, and the recommendation has found strong resistance from the faculty. As stated in the report, there is a general belief among basic science faculty members that lectures are both the most effective and the most efficient method to teach students. It is difficult to argue against the efficiency of lectures, any type of small group teaching format certainly requires more faculty effort than a lecture. The effectiveness question is the crux of the matter. But before discussing effectiveness, I would like to note that in my teaching career which goes back about 17 years, I have never met students that had any problem with the concept of replacing lectures by small group teaching activities, and I would not put much credence in this type of argument, coming from schools trying to defend their adherence to the lecture format.

It is important to establish at the onset that I am a product of a traditional lecture-loaded curriculum, that I was an obsessive class attendant in school, and that I deliver 37 lectures every year, to the students enrolled in the Microbiology/Infectious Diseases and the Immunology courses, apparently very well received by my audience. At the same time, I also have introduced a variety of non-lecture activities in my courses, both involving small group and computer-based teaching. The small group activities are self-contained case-based exercises, and usually follow one or several introductory lectures which cover the most important aspects of the cases in question. As a small group leader I have quickly realized that few of those students that I saw in class, following my lectures with great attention, do recall many of the significant aspects of the lecture a few days after its delivery Indeed, I have come to the conclusion that most of the factual knowledge required for success in our multiple-choice exams is acquired in the few days of cycle-studying preceding each test. This is a talent that our students have developed to perfection ? they can memorize great chunks of information in very little time. The problem is that a week after the test, most of the information has been forgotten.

Therefore, the questions of efficacy has to be linked to other qeuestions, such as retention of information and the development of self-learning and problem-solving skills. The importance of self-learning is obvious, once we consider the shortness of our memory and how much we have to depend on continually educating ourselves to process in our careers. One would think that basic scientists are acutely aware of this need. But then if this is so obvious, why continue encouraging mindless memorization as the most significant tool for survival? To blame it on the MCQ format used in testing is a very poor excuse, when it is has been amply demonstrated that this format is amenable to test the ability to interpret data, simple reasoning, and even some degree of problem solving. But, if faculty do not believe that the MCQ format can be used for testing something other than factual recall, other formats are available. What is hard to understand is why we continue perpetuating a situation which should be of concern to everyone.

Are the small group formats better at improving retention of concepts, and helping the students to develop self-learning techniques and problem-solving skills? The question of retention is the most difficult to answer, even if intuitively one would believe so. I tried to approach this question by performing statistical analysis of the performance of students in a group of 15 questions which was included for three consecutive years in the final exam of our Immunology course, reflecting the content of topics which used to be taught in the lecture format, but in the two years preceding the study, the lectures had been replaced by small group case-based exercises. The results, summarized in Table 1, suggested that the performance improved after lectures were replaced. The source of written information remained identical after the lectures were dropped, but a list of objectives for each chapter was made available to the students after the lectures were cancelled. So it could be argued that the distribution of objectives helped the students master the subject and that case-based teaching was not the sole factor responsible for the improvement.

A second piece of anecdotal information has been provided by the much maligned Step1 of the medical licensure exams, in which the microbiology sectionā€™s scores for our students have showed a steady increase in the last few years, as the percentage of time dedicated to case-based and computer-based teaching has increased in the Microbiology/Infectious Diseases course (which I also direct), while the overall mean score for our school has shown inconsistent fluctuations. For example, last June, our studentā€™s score in the microbiology section exceeded by more than 20 percentile points the means score in the whole test. But, again, other factors could contribute to this difference, such as the use of clinical vignettes and data sets in our tests (ongoing for many years before it became a fashionable practice), or the distribution of Boards preparation materials in May, and it may be that those efforts are finding some reflection if our students performance.

On the other hand, any small group activity is going to be an improvement over a lecture when it comes to developing studentā€™s self-learning and problem-solving skills. In a traditional curriculum, time constraints prevent us from developing small group activities in which library search is essential. As an alternative we require all our students to write a three page referenced paper on a current immunology topic, and this activity certainly involves reference searching and trips to the library. There is also a self-learning in our small group activities, although is centered on syllabus and textbook consultation. The students work in groups of four and are instructed to bring four different sources ? the course syllabus (which is fully indexed) and Microbiology, Immunology, and Internal medicine textbooks. The number of students purchasing textbooks ? and using them ? has shown a marked increase, and that is a welcome sign. Some will try to use review and summary books, but soon find that those are useless for this type of purpose. And one would hope that it is not necessary to discuss the advantage that any process involving the resolution of a simplified clinical problem has over a classical passive learning activity such as a lecture when it comes to developing problem-solving skills.

Having seen close-up the advantages and disadvantages of several formats with which I feel totally at ease, my conclusion is that we do lecture far too much. Lectures can indeed be cut by at least one third or one half in most courses and be replaced by more effective formats. Lectures should be reserved for teaching essential concepts and to facilitate the learning of complex issues. All clinical correlations should be planned in formats other than lectures ? computer simulations, base-based teaching, conferences, papers, etc. And an effort should be made to identify areas of content in each course which would be better taught in an active learning modality, including laboratories. For example, lectures in anatomy could be virtually eliminated, the dissection laboratory and computer-assisted teaching would provide a considerable more efficient mix, particular if integrated with other activities illustrating the unquestionable clinical relevance of the discipline. The much derided ā€œbug paradeā€ of microbiology courses could easily be replaced by case-based teaching activities and computer simulations. And similar examples can be found in all basic science courses. Judging by the response of my students, all efforts to lead them to learn in an active modality are welcome and greatly contribute to their enjoyment of the discipline. A positive perception by the students is extremely important for their collective performance. They are more likely to give their best effort to a demanding course which challenges and motivates them, then to a run of the mill series of lectures, which are not often well planned or well delivered, and which inevitably will create the impression of the students that basic sciences are dull repositories of facts and useless trivia, collected and delivered without much thinking. Who would believe that basic scientists would excel in creating such a distorted view of their disciplines? But that, perhaps, should be the topic for a discussion on how to improve the perception of the basic sciences by medical students.
REFERENCES:

1.ACME-TRI Report: Educating Medical Students. AAMC, 1992.

2.Physicians for the Twenty-First Century ? The GPEP report.