A key pillar of project-based learning is the inquiry process through which students explore a problem and the content which they are required to learn as part of the project. Under this theoretical model of ‘best practice’ PBL, students get to make choices about what they want to learn and what information will help them progress in the project. Students then learn through discovery by exploring the gaps in their knowledge. The teacher guides and facilitates the process, rather than engaging in regular explicit teaching.
Explicit teaching can also be somewhat devalued by some schools of thought which promote PBL’s value as a way of helping students develop transferable thinking and interpersonal skills. We’ve heard the sentiment that ‘The only thing that matters is the skills; content is now more accessible and less important’ from many schools when planning their PBL units. This position can obscure the importance of explicit teaching as a cornerstone for student learning.
In our experience, any approach to PBL which does not both value and build around the explicit teaching of content is misguided. Not only is the frequent incorporation of explicit teaching likely to deliver better learning outcomes for students – John Hattie’s work indicates direct instruction has a higher effect size on student learning that inquiry-based learning – it also places students in a better position to use what they have learned to create innovative solutions to the problem they are tasked with solving. In this article, we’ll explain how we think you should approach the explicit teaching of content within a PBL unit.
The role of explicit teaching in PBL
As Jaye Dunn outlined in her overview of the approach taken to PBL by Epping Boys High School, explicit teaching should be the foundation of every PBL unit and the first place that planning should start. However, we have often seen units designed where student learning is expected to occur largely through inquiry and student-driven investigation.
As noted above, there are problems with this approach. The first – and most obvious – is that students gain only a superficial understanding of a concept, instead of the more rigourous comprehension which would be developed through multiple lessons of teacher-driven instruction. There is also the risk that students do not cover all the content required to be taught in their inquiry process, thus creating gaps between their working knowledge and what the curriculum requires them to have learned.
The other risk which is posed by a deficit of explicit teaching is that students won’t have the content knowledge to interpret and understand stimuli related to the problem and potential solutions. For example, developing a solution for mitigating the impacts of global warming and rising sea levels requires not only a working knowledge of the causes of these phenomena but also the scientific intricacies of how they occur. Are rising seas caused only by melting ice and, if so, do we need to be more worried about melting sea ice or melting land ice? Or is there another reason that sea level rise occurs even if we can halt the melt of the polar ice sheets? Unless students have the content background first, they can’t fully understand these concepts or the materials which they explore to understand the impact of the problem.
The same holds true when students reach the point of developing solution ideas. A good definition of creativity is associative fluency, which is the ability to connect two ideas or concepts in a new or novel way. The classic example of this was the invention of the microwave oven, created when an employee at a company producing military radar equipment walked past a source of radiation and noticed that the chocolate bar in his pocket had melted. Connecting the heat energy produced by radiation and the quick warming of food is a great example of associative fluency; however, the key is that it required someone to have deep content knowledge to make that creative leap. The same is true for students in a classroom working on their own creative solutions to a problem posed in a PBL unit. Unless they have deep content knowledge, they will be unable to apply that knowledge to the problem in a creative way.
How to structure a PBL unit to promote explicit teaching
Start with the content, not the problem. Too often, schools create a PBL unit based on the problem students must tackle and then fit the content around it. Instead, it is important to start with the content and work backwards. When designing a PBL unit, think about what problem knowledge of the content will help students understand better, or which aspect of the problem it might allow students to focus on. This should then extend to the type of end product students are working towards. For example, different aspects of a Science curriculum (ecosystems in biological sciences, states of matter and the particle model in chemical sciences) might lend themselves to different aspects of exploring the problem of ocean plastic waste, which in turn will require students to solve the same problem from different angles.
Structure student inquiry around content to be taught. A concern we sometimes work through with staff is that, if students are given the opportunity to develop their own inquiry questions for the project, they might ask questions which are relevant to the problem but which are beyond the scope of the content that needs to be covered. Alternatively, they might miss areas of inquiry and may not ask the questions which would enable content to be introduced to the project. To reduce the risk of inquiry not matching closely with curriculum, the students’ inquiry should be structured around key knowledge areas. Students should be given discrete ‘knowledge areas’ for which they are to develop inquiry questions, which ensures their inquiry is focused on the elements of the problem which are to be addressed through explicit teaching. To continue the above example on ocean plastics, if the PBL unit was aligned with the chemical sciences topic, most of the ‘knowledge areas’ for which students should develop inquiry questions might relate to plastic itself – what it is made from, what its properties are, why it can’t be recycled easily, why it can’t be burned, and why it isn’t biodegradable. In this case, we might not include a Knowledge Area on ecosystems and energy flow through food chains and food webs – though this would help students understand one aspect of the problem, it would not align with the content to be taught.
Sequence explicit teaching and project work. A good rule of thumb across the Define stage of the project – where curriculum content should primarily be introduced – is that you should alternate lessons between explicit teaching and application of content to the project. This ensures that teachers have sufficient class time to cover the curriculum through direct instruction, whilst also providing an immediate and hands-on avenue through which students can transfer their learning to the project context. This means that the student understanding of the problem should evolve with the gradual increase of their content knowledge. Again, this requires careful planning to ensure that the sequence in which content is taught can align with the way someone would ordinarily explore the problem. We suggest breaking your teaching curriculum down into composite parts, changing the order where possible so that it better matches how you want students to explore the problem, and then creating a hands-on task for each separate content component which will help students transfer their understanding to the project.
End product requires content application. PBL can be a powerful tool to enhance student learning but, for this to occur, students must use what they have learnt from a content perspective in the design of their final solution. In his book Why Don’t Students Like School?, cognitive scientist Daniel T. Willingham speaks about memory being the residue of thought; we remember what we think about. Therefore, for PBL to enhance long-term content understanding and retention, students must be thinking about what they have learned when they are creating their end product. If, for example, students explore the problem of ocean plastic waste from a chemical sciences perspective but then create a website as their end product to better educate people about the need for recycling, they won’t have been grappling with their chemistry understanding in the design of their solution. They won’t have been actively thinking about how to transfer their understanding to their solution design, so the long-term learning impact of the unit will have been compromised.
We believe that PBL isn’t just a great way to engage students and develop their thinking and interpersonal skills. It is also, when designed and sequenced successfully, a powerful tool in enhancing and deepening student learning outcomes. A shift in how people think about explicit teaching and its role within PBL must occur; rather than the two being incompatible, they in fact work together to create a rich learning environment.