Getting the balance right when assessing PBL
We get asked more questions about assessment in PBL than any other topic. It’s something that is front of mind for every educator in every classroom. Each school has a slightly different approach to assessment and each teacher has their own preferences which they’ve developed through years of experience. But a PBL unit creates an entirely different assessment paradigm; one that can stump even the most experienced practitioner.
Let’s consider some of the variables that make assessment complex in PBL. Students aren’t simply doing rote application of concepts; they’re transferring their learning to new contexts and using what they learn to tackle real-world problems. Students are working in groups where their progress and results in part depend on the work of their peers. And each team creates a single end product, making individual assessment difficult.
So how do you untangle all this to create a rigorous but fair assessment framework? We’ve listed our top tips below.
Decide what you are assessing
The obvious but often overlooked question is to make a very deliberate decision on what you are going to assess across a PBL unit. Will it be the entire body of content knowledge from a particular topic, or just a few key concepts? Will you only assess student skills rather than content knowledge, or will you assess both? And if you assess student skills, will you try to assess a wide array of skills or will you focus only on (for example) collaboration?
This is an individual decision but we suggest that you make it depending on the unit that you are running. We think you should:
Only assess content which is central to the PBL unit and which students will need when creating their end product (see below). Any content which is slightly related but mostly tangential should be overlooked.
Similarly, assess core skills that will be used multiple times across the unit. This gives you the chance to take multiple proof points of skill demonstration and gives students the chance to improve how they perform at that skill.
For example, in our To Mine or Not to Mine unit, students require Science content knowledge to examine how different minerals form within the Earth’s surface. They must apply that knowledge to determining whether a specific geological location might possess minerals worthy of extraction. They must also apply content knowledge on the separation and filtration of mixtures to identify the most effective extraction method for mining those minerals. This is the key content needed across the unit, so we build our formative and summative assessment around these knowledge areas. The key skills students need in this unit involve communication and listening, given the unit requires them to negotiate on whether the mine should proceed based on the views of different stakeholders. Again, we limit the assessment of skills to the ones which are used repeatedly across the unit.
Assess content knowledge individually
Students work in teams across a PBL unit. This creates headaches for educators as they attempt to assign an individual mark to students based on their content knowledge. This is challenging because in a team the stronger performers might carry their teammates, so it is unfair for everyone to receive the same mark.
Our strong suggestion is that every student should be assessed individually on how well they apply their content knowledge across the project. This should mostly occur in the first part of the unit – across the Empathise & Define stage/stages, if you are using a Design Thinking structure – where students are transferring content understanding to the real-world context to explore how what they are learning informs the problem, its causes, and its impacts. We recommend a discrete set of tasks which scaffold student knowledge transfer to the project, and which can therefore be assessed based on your curriculum.
Though students are working in teams and can work together to complete these tasks, each student must complete each task individually – at this point in the unit, there is no team submission. Because each student must create their own submission, it is easy to assess content understanding individually. This also ensures each team member has the same base knowledge leading into the more complex parts of the unit where they must create their end product; which, in turn, increases the chances that each team member can actively contribute.
Assess skills individually and as a team
When assessing skills across the project, it becomes a little more complex. Some skills can easily be separated from the group and assessed individually, whilst others need to be assessed as a team. However, there are ways of structuring team assessment to ensure that students who do less or who are dragging the team down can’t affect the grade of the more proactive students.
Most skills can be reduced to an individual component as well as a team outcome which can also be assessable. Some examples are:
Teamwork. Teams can be assessed on how well they create a plan for the roles and responsibilities which must be fulfilled across a task; individuals can be assessed on the extent to which they fulfil their role or responsibilities.
Creative thinking. Individual students can be assessed on the number or quality of original ideas that they generate; teams can be assessed on how well they build on individual ideas to create an agreed-upon team solution.
Reflection. Individual reflection can be assessed for student metacognition, whilst team reflections and discussions can be assessed based on the outcome (what the team decides they need to change and how they plan to do so).
We like the blend of individual and team assessment because it balances individual determinism with a need for genuine collaboration and co-reliance. Students can demonstrate varying individual prowess at a skill despite being part of a team – so they needn’t fear that another student will ‘bring them down’ – but there is also a requirement that they work together both for the good of the team and for their own ‘score’ or grade.
Assess the end product as an individual AND as a team
When it comes to an end product, we’ve seen different approaches to assessing it that all work. Some schools don’t assess it at all, instead relying on formative assessment across the unit. Some schools assess the quality of the output; others assess the quality of the thought that went into it. Again, each approach has its place and the most appropriate one for you will depend on your context. However, as a general rule, we’d suggest:
Don’t assess the end product on form or function. Generally, we recommend against assessing the end product based on whether it works or whether it does exactly what it is meant to do. Unless you are in a Design & Technology or a Media classroom, students are unlikely to produce highly-finessed end products. They might run out of time, or their product might not work as expected. They shouldn’t be penalised for this. Instead, we want to assess them on the thinking that went into the design of their product. The thought behind the product is where the transfer of content knowledge occurs.
Don’t assess the end product itself against curriculum. As it is a collaborative effort, it is hard to separate out individual contribution to assign a mark. Instead, ask students to individually write a short pitch document which accompanies their product. This should summarise the team’s rationale for creating this product and what impact they hope it will have on the problem or real-world context. If necessary, it can include a sketch or design. Within this document, each student should articulate how the application of content knowledge has led them to this solution. This makes it easier to assess against the curriculum individually.
Assess the team on how they approached the build. The team can be assessed here but, again, avoid assessing them on their end product. Assess them on the process they followed to create their end product. Was there collaborative input on the product’s design? Was there a division of roles and responsibilities in the building of the product? Was the product tested and learnings from the test folded back into another iteration?
When you assess in a structured fashion, you can longitudinally track student skill development over time. You’ll become aware of the weak points in students’ collaboration or critical and creative thinking skills arsenal. And, by helping students work on them, you’ll be setting them up for success long into the future!
Do you know an educator who would be interested in learning more about how to assess PBL? If so, please share this article with them!
If you are passionate about teaching collaboration and want to learn more, get in touch with us at hello@curaeducation.com. We’re always happy to exchange ideas with our PBL community!