PBL in practice

After the discussion on some advantages of PBL as compared with more traditional learning we should like to describe how PBL can work in practice. Let's start with a patient problem, "Peter"

Peter is a 15 year old black secondary school student reported in a health centre with a complain of a light brown skin patch over his right shoulder of six month duration. The skin is not sensitive to touch.

After a thorough reading of the case maybe some students do not understand exactly what a skin patch is. These students may than ask for clarification to the other students. A student who is more familiar with skin patches might explain more about the patch, for example how it looks like exactly, how big it can be and so on, in order to make it more understandable to the student.
It is important in this stage that asking to clarify something does not mean that a discussion about such a subject should start. Only some additional information is
allowed to be given for a better understanding of these students.
The students are then asked to identify and define the problems in the case study. In the case of Peter, the problems are a light brown skin patch and an insensitive skin patch on the right shoulder. The students are then stimulated to explain the problems as good as possible. The explanations can be in form of hypothesis suggesting the possible causes about the problem and the mechanisms which brings about the problem. For example a student might say that there are a less number of pigment making cells in the skin patch compared to the rest of the body. Yet another might say that peter could not feel on the skin patch because the sensory nerves are damaged. A student who is more familiar with the subject might propose that the discolouration of the skin patch is caused by the damage of the sensory nerve.
At this stage all explanations, i.e thoughts of the students are accepted and regarded as possible hypotheses to work upon to understand the problems of Peter.
After this initial discussion, where in all the group members have had their say about the problems, the group has to formulate (decide) upon its own learning questions/issues based on their stated explanations and hypotheses. The students have now to determine the gaps in their knowledge about the normal and abnormal features of the skin and nerve supply to the skin. At this stage the students might decide to find answers to such questions as " What is the structure of a normal skin?" And, "Why is the colour in the skin patch different from the other areas of the body?" or "What is the nerve supply to the skin? "What happens to the skin when the nerve supply is damaged?"
Once the list of learning questions/issues are agreed upon the group splits up so that each student can undertake his/her independent learning to find answers to the questions raised. This self-study can take place in the library using books, magazines, posters, tapes and video clips as the case may be. This is the process of active learning and discovery of the student.
In the next group session, which may be few hours or a couple of days later, every students reports about his/her findings regarding the learning questions. During this session the other students and the facilitator have the opportunity to raise questions to stimulate the students to explain the findings. The end should be that the students should be able to fill the gaps in their knowledge of the features of the normal and the abnormal skin. In addition the students can make their own notes about the newly acquired knowledge.
If there are still to many gaps, the self-study can be rehearsed with the same case study and more questions, or a similar problem.

PBL is a way of gathering information to understand problems more thoroughly. But also in PBL course students must be trained in physical examination, and in doing a systematic history. Knowledge must be applied, and these examination techniques must be learned in the same way as in more traditional learning environments.

Different steps more in detail

Most processes and methods can be broken down to their different parts and so it is with PBL. It too has a chain of 6 steps, which can be learned from the previous paragraph. They form the basic structure of the method and, while the more experienced may not follow these six steps rigidly they are very helpful for those who are beginning to use PBL. See table 1
We shall now discuss these in more detail.

Table 1. Different steps in PBL

Different steps in PBL
  1. Clarification
  2. Problem list
  3. Explanations/hypotheses
  4. Formulation of learning questions/objectives
  5. Individual study (self directed learning)
  6. Synthesis and application

Step 1. Clarification

In this stage the students may ask for clarification of terms or concepts, so that the problem can be made clearer and more easily understandable. When we look back to the problem of Peter, a student may ask what a skin patch is. Other members of the small group (tutor group) may explain this, who uses their prior knowledge. In most small groups students have different levels of knowledge, especially when there are combined learning groups of members with a background in TB or leprosy. But one thing has to be made perfectly clear. At this stage, that clarification does not mean discussion or even trying to find solutions as soon as possible. We stress this last point again and again.
In every small group the different members have, in technical jargon, different " entering characteristics', when they start a course; age, experience, back ground etc., and it is very important that the more experienced ones do not try to dominate the group and try to jump to conclusions about the problem. Sometimes they do not allow the group to go through the problem step by step as a learning exercise, in order to see what kind of information is needed to understand the problem better. When a case problem is being studied for example, sometimes, at the very beginning, students just ask for more data from the history and the laboratory, just to solve the case as soon as possible. We must stress, for tutors working with PBL, the important distinction between problems as a basis for learning, and problems to solve: these concepts are related, but are distinguishable from each other. We will work out this difference more in detail later on.

Step 2. Problem list

What is the problem? In most patient problems, the general problem consists of different sub-problems, which are related intimately to each other. Sometimes, these are but not always, easily to define. In the case of Peter the most important problems are the light brown skin patch and the insensitive skin patch.
At this stage the students begin to bring together their thoughts and ideas about the problem, and their tentative thinking about the problem is structured. They should make a problem list (see table 2). This list is the result of the discussions in the pervious step.

Step 3. Explanation/ Hypotheses

Not only are different kinds of problems listed, but the students are also invited to think about different problems, and to give explanations for these and for the phenomena, which they have encountered. They therefore begin to make hypotheses and plausible suggestions for causes.
Some sceptical people might argue that it is unreasonable to expect students inexperienced in medicine to give an opinion about a medical problem, as we mentioned above. But this is to deny that they have at least some background knowledge. They are thoughtful and they can be expected to formulate hypotheses or explanations for the listed problems. The explanations can not be very specific and elaborate, but the students are stimulated to think and to develop this skill of the formulating preliminary hypotheses as quickly as possible: this skill will help them later in their work in health care, in whatever work they do. We will discuss this later in the chapter on problem-solving skills. At this stage the formulation of possible explanations will help the students to ask themselves "what further information do I need in order to understand the problem better" As they suggest possible explanations, they think about additional problems, and this challenges the student to study, to gather information, and to consider to what depth they understand the patient's problems and complaints.
For a list of problems and hypotheses, identified by students, see table 2

Table 2. Peter; Problems Hypotheses
Problems

Hypotheses (explanations).


Light brown skin patch






  • Birth mark
  • A Scar due to previous injury
  • Fungal infection
  • Bacterial infection e.g. leprosy
  • Drug reaction
Insensitive skin patch



  • Damage to skin during previous injury
  • Traditional medicine application

Step 4. The formulation of learning objectives/questions

This is a very important step and is in sharp contrast with traditional teaching. When lectures dominate the course and teachers decide what has to be learned, what books should be read, what references to articles have to be given to the students- in fact the teacher is guiding the student in his learning. In PBL the teacher does not decide what the study content must be. In the small group (under the guidance of the tutor) the students make the decisions themselves. The development of the learning issues proceeds throughout the case discussion. On the basis of the different problems they have listed, with the possible explanations, they formulate the questions to which they would like to have answers. Another very important step in this stage is for them to discuss which questions are the most important ones for them to study. At the end of each session, the tutor group together with the tutor (facilitator) reviews the list of issues and determines which are the most appropriate to enable them to understand the problem better. A list of study questions formulated by a group is presented in the table 3
If PBL is to be effective, every student has to study the questions individually, but some students may wish to explore some subject(s) in more detail. They should be encouraged. Students who want to go deeper into the subject gain confidence and immediately become autonomous in their learning, independent of the tutor. The initiative could also help less inquisitive and enterprising students who would be shown how a student really could become an independent learner.

Table 3. Peter; Study questions

Study questions
  • What are the characteristic features of a normal skin?
  • What are the functions of the skin?
  • Why is the color of skin different from one person to another and from race to another?
  • What is responsible for the discoloration of the skin over Peter's right shoulder?
  • What is a birthmark?
  • How do micro organisms enter the body through skin
  • Is there any link between the discoloration and the loss of feeling in the skin patch?

Step 5. Individual study (self directed learning)

When the small group functions well as a group, the differences in energy, ability and intelligence between its members are less evident than they are when these members study by themselves, and then bring back the results of their reading and synthesis of what they have read, and their conclusions to the group. Each one can use the library, and can seek its books journals and perhaps some prepared instructional units, the help of an expert tutor or the help of other people, to get further information. Some will do this more thoroughly than others. If a programme in PBL is to succeed it must be backed up by good library resources and, ideally, helpful library staff. Those who are responsible for courses and units must therefore ensure that that the necessary resources are available when the students need them: if they are not being found the students will become frustrated and lose interest. Simple things, such as there are not being enough places in the library where a student can sit and work, may prevent a programme of PBL from being successful. When these facilities are accessible students will use them very frequently.

Step 6. Synthesis and application

At this stage the students present to the others in their group what they have found from their inquiry and their reading. It is important that everything is made clear so that they all understand what the others have found. Every student must have an opportunity to present what he or she has found. At the end of the session the group must check whether they understand the problem of Peter much better. When necessary, if new questions are raised, the group should spend another session on the problem. But if they are satisfied that they have done enough and have got enough, information the group can move to a new problem.

 

Do it yourself 1

You are invited now to read the following case very carefully. After this you can make your own problem list, give your explanations/hypotheses for these problems and list your important learning issues.
When you are finished you can compare these with the work up of a small expert group. See table 4 and table 5

Olumide

Olumide, a 12-year old apprentice mechanic, who was forced to leave school due to financial problems, was brought to the leprosy clinic by his father for admission into the leprosy settlement. Olumide was unhappy when he saw the aged and crippled patients in the settlement, facing his own bleak future. Olumide was brought to the clinic because of bilateral footdrop and clawing of hands with severe reactive skin lesions. Olumide's father was determined to leave Olumide in the settlement, because of the village gossip. Olumide had no choice but to stay in the camp. His father bade him goodbye and left. 


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