The problem with Problem-based Learning…
…and our thoughts on them.
Hello and welcome to the 43rd edition of our fortnightly newsletter, Things in Education.
We have written about project-based learning a few times in the past, but today we focus on the other PBL – problem-based learning. If you look up what problem-based learning is, you will find some variant of: “Problem-based learning (PBL) is a teaching style that pushes students to become the drivers of their learning education. Problem-based learning uses complex, real-world issues as the classroom's subject matter, encouraging students to develop problem-solving skills and learn concepts instead of just absorbing facts.” There are many reasons why PBL is better than direct instruction for student learning and retention. At the same time, there are many easy ways to get PBL wrong in the classrooms.
Focusing on the solution of the problem
If you go back to the ‘definition’ of PBL in the previous paragraph, you will notice that there is nothing about students needing to find a solution to the problem. The approach is meant to develop problem-solving skills and learn conceptually. This is a common misunderstanding that a lot of educators have – that PBL must end with a solution to the problem. However, PBL must end when the learning outcomes have been met. Let’s think about this – we are giving students “complex, real-world issues…” to solve. Experts with a lot of experience are trying to solve these problems. We cannot expect students to solve these problems in a matter of days. So, the ending point must be when age-appropriate learning outcomes have been met.
Student solutions to the problem are generally trivial
As we wrote earlier, getting students to solve problems that the world is struggling with is an impossible task. Solving a problem presupposes prior knowledge in the problem solver, while PBL is a way of learning. Moreover, to solve complex problems, deep structure knowledge is required. We have written about surface structure knowledge and deep structure knowledge earlier. This dichotomy becomes more apparent when students try to find solutions with little or no background knowledge.
So how do we approach PBL then? Firstly, remove the assumption that students need to find solutions to the real-world issues that they are working on. Secondly, ensure that the learning outcomes are met while using the problem-solving approach. For example, if the problem is to find more sustainable ways of living for the Indian population, and if the learning outcome is to be able to find a measure to compare sustainability of two different practices, then once the students understand how to calculate the carbon footprint of driving an electric car versus driving a petrol-powered car, the learning outcome has been achieved. The problem in the problem statement has not been solved. So don’t force students to come up with trivial solutions just for the sake of getting a solution. Focus on the learning outcomes.
Pitching the problem at the right level
Although we saw the definition of PBL at the beginning of this piece, there is another school of thought which encourages that the problem be posed to the students at a level which is challenging but solvable. Here is an interesting problem that is posed in biology by Christian Moore Anderson, a notable biology educator. The lesson begins with showing the class this simple diagram of how glucose flows in our bodies. The problem: how does the body deal with the unreliable levels of glucose – high glucose when we eat, while low level of glucose when we sleep at night. Through a process of guidance, the students will realise that there is a need for a storage of glucose and a valve to open the flow toward or away from the storage.
This is a problem that the students can solve. It has been pitched at the right level, and students while solving learn about the function of the liver, which stores glucose in the form of glycogen and the valves – the hormones (insulin and glucagon).
PBL needs direct instruction or some other pedagogical support
In the example above, the teacher uses a problem-based approach, which is coupled with guided inquiry. In fact, most of the evidence we have suggests that PBL works best with some amount of direct instruction. With younger students – up to grade 5 – direct instruction followed by a small problem to solve works to some extent. Mostly PBL is not very effective as a pedagogy up to grade 5. For students above grade 6, problem-based learning followed by some direct instruction seems to be the most effective. A lot of this evidence comes ‘not from India’. And given that Indian students are even more used to direct instruction, we need to be careful about using PBL without proper planning.
PBL works for conceptual knowledge
Problem solving is a useful pedagogy when it comes to learning conceptual knowledge and not so much in terms of procedural knowledge. Let’s take the example of a problem such as writing a letter to the municipal commissioner of your city to inform them of the number of potholes on the road and how this has been a problem for a long time. For such a problem, if the learning outcome of a writing class was for students to understand what type of language to use, choice of active or passive voice, whether the writer should use contractions or not for emphasis, whether questions or statements will be more impactful, then PBL works. But if a teacher wants to use this problem to get students to learn the structure of the letter, parts of a letter, etc., PBL may not be very useful and instead be superfluous.
To summarise, ensuring focus on meeting the learning outcome and not on coming up with a real-world solution, pitching the problem at the understanding level of the students, combining PBL with direct instruction or guided inquiry, and using PBL for conceptual knowledge and not procedural knowledge can make this pedagogical approach more effective.
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