Problem solving learning: Applications in medicinal chemistry

American Journal of Pharmaceutical Education, Spring 2000 by Dimmock, Johnathan R

This study describes the implementation of a didactic methodology in medicinal chemistry known as problem solving learning. Students were divided into groups of four to nine students predicted to have varying aptitudes in these classes based on their performances in previous chemistry courses. Prior to coming to each class, students are required to read a specific portion of the class notes and answer the questions posed at the end of each reading assignment. A problem set based on the designated reading is distributed to all students who then work in the small discussion groups. At the commencement of the next class, answers to the problem set are presented by the instructor or alternatively by students from one or more of the groups. This approach is viewed positively by the students as a stimulating and challenging way to understand medicinal chemistry.

INTRODUCTION

For a number of years, the author has taught half of a compulsory medicinal chemistry course in the penultimate year of the 1 4 undergraduate program at the University of Saskatchewan, as well as an elective on drug design in the final year. The presentations were made using a traditional "chalk and talk" method whereby the information was placed on a board and dutifully copied by the students.

However a number of factors caused the author to re-evaluate this teaching methodology. In the first place, could not the time be better spent than the teacher honing skills of dexterity with chalk and the student in developing note-taking skills? Secondly, little time was available for the students to think about the subject matter, to ask questions or to discuss the material with fellow students or the instructor. Thirdly, the closed book examinations consisted of multiple choice questions. Although this method of evaluation presented novel problems to the students, it inflicted excessive emphasis on memorization of the material and in addition only right or wrong answers were permitted. Students did not have the opportunity to explain why they had reached various conclusions which, if ultimately incorrect, would deny them some credit for at least thinking correctly part of the way. Clearly the point had been reached for some radical changes in both teaching methodologies and examinations.

Recently an episode provided sufficient motivation for changes when the attention of the author was arrested while reading the introductory comments of Medieval Church History. This book was written in the 19th century by Dr. R.C. Trench who at that time was the Anglican Archbishop of Dublin. He was a prolific writer and possessed an incredible wealth of knowledge. Yet in discussing teaching church history to "girls of the upper and middle classes," his approach to the matter seemed inordinately unimaginative as illustrated by the following partial quotation from a 155-word sentence.

"How far the wearers of bonnets would bear the strain of competition with those thus assumed to be in exclusive possession of brains... on this I give no opinion; but having regard to receptive capacity, to the power of taking in, assimilating, and intelligently reproducing, what is set before them, my conviction is... that there is no need to break the bread of knowl edge smaller for young women than young men...(1)

A red flag was raised, i.e., is this all there is to teaching namely to have students receive, assimilate and reproduce knowledge? Thus commencing with the 1995-96 academic year, didactic lectures were eliminated and instruction was given solely by a procedure which may be called problem solving learning (PSL). The aim of this presentation is to describe how PSL has been applied to teaching medicinal chemistry at this institution although the principles involved are applicable to other subjects including all of the disciplines in pharmacy schools.

MODUS OPERANDI OF PSL

A description of the various stages in utilizing PSL follows.

Division into Groups

The first action to be taken prior to the beginning of the academic year is for the students in each class to be divided into groups. In the opinion of the author, the ideal size of the group is four to six students which is the situation in the drug design course. However the dearth of available small rooms mandates that the medicinal chemistry class of 75-80 students be divided into nine groups each containing eight to nine students. Self selection into groups would likely lead to markedly divergent levels of ability and attainment(2) and the clusters of students should have similar capabilities. The division into groups is based on their performance in specific classes taken in preceding years namely an organic chemistry course for those students commencing the medicinal chemistry class while individuals electing to take the drug design course are divided into groups which are determined by the marks obtained in the medicinal chemistry class taken one year previously. The way in which students are divided may be illustrated for the medicinal chemistry course. The nine students with the highest marks in the organic chemistry class are placed in nine different groups. Then students with marks ranked at positions 10-18 in organic chemistry are sequestered into groups 1-9 and so forth. Finally the nine undergraduates with the lowest marks in organic chemistry are placed in dif ferent groups. In this way, the weaker students can be assisted by the input from those who are fluent in medicinal chemistry and drug design. However the names of students in each group are arranged in alphabetical order thereby providing no information as to individual performances in the courses taken previously. All students remain in the assigned group for the entire course and ideally team learning(3) will ensue.