Adam Robbins Education

I think checking prior knowledge is a really important part of teaching any new concept. I also think it is often overlooked. When I watch lessons in the schools I visit I often see teachers mention prior knowledge but not specifically check it. I think this often occurs because of four main issues:

1. Time
2. Underestimating the importance of prior knowledge
3. A fear of reducing students confidence if they don’t know
4. Teachers overestimating their students knowledge

Before we look at these issues let me give you an example of what I mean by checking for prior knowledge. Feel free to skip down if you are familiar. This example is from science but equally relevant to other subjects. I’ve also chosen a topic that is purely declarative knowledge to keep the example simple.

Mr T is going to teach a year 10 class about atomic structure for the first time. After his students entre and complete the retrieval practice at the start of the lesson he instructs them to get out their mini-whiteboards and asks them the following questions:

• What is all matter made from?
• What do we call a substance made of only one type of atom?
• Draw me the particle diagram of a solid
• Draw me the particle diagram of a liquid
• Draw me the particle diagram of a gas
• Where can we find all the elements listed?
• What group is Lithium in?
• What period is chlorine in?
• What element has an atomic number of 13? 
• What is the charge of a proton?
• What is the charge of a neutron?
• Where are electrons found in the atom?
• What is the mass of an electron?
• Which subatomic particle has a negative charge?
• Where are protons found in the atom
• Which subatomic particles have a mass of 1?
• What subatomic particles are found in the nucleus?

With each question he uses a strong routine (Show me) and gathers the data informally, whilst providing the correct answer to the students verbally. 

“I pity the fool who doesn’t check for prior knowledge using a high-ratio, low-threat means of participation SUCKA!”

Back to the 4 barriers:

Time

I think teachers are always obsessed with time. There is a constant feeling that there is never enough time. Checking for prior knowledge does take time. However it doesn’t take much time if routines are tight and behaviour is strong in the class. It is time well spent because it can save time overall. It can save time by allowing the teacher to begin their explanation further along the narrative if the students have strong prior knowledge and it can save time crucially because the explanation will be more effective due to the priming of the relevant information. There is also a reality that it might open a can of worms and you might find out that students have very poor recollection of prior knowledge. This can eat into time with re-teaching important ideas. So there is a risk that has to be taken when it comes to the impact on time. One of the ways we can save time is to ask fewer questions. In Mr T’s case we could ask him to reflect and see if all the questions he asked were important. When looking at the questions you might feel that there are potentially less relevant questions being included. The questions about the periodic table are potentially not relevant to the structure of the atom, as this lesson will focus on the subatomic particles and their properties. On the other hand we could argue that by activating ideas around the periodic table Mr T is trying to make links between what they will be covering today and how the periodic table is arranged, something that will be needed later in the topic. This might increase the students’ flexibility of knowledge. This is probably a trade-off situation whereby Mr T needs to weigh the time it takes to go through the questions with the potential benefit in ensuring students link ideas of the periodic table and atomic structure.

Importance

Checking students’ prior knowledge of the topic before they begin their explanation, is hugely important. We know that one of the most important factors to determine how easy students learn new information is what they already know. We also know that quizzing is an effective learning strategy. Combine this with the fact that often teachers don’t keep the same students between years and you get a strong case for checking the prior or prerequisite knowledge needed before teaching anything new. To me, once this is fully understood, it becomes impossible not to prioritise prior knowledge checking at the start of each explanation.  

Fear of reducing confidence

I think this is a sensible thing to think. Teachers are compassionate and want their students to feel successful and motivated in their lessons. I think this is not a compelling enough case to not check prior knowledge though. 

If we look at the back half of the questions it is highly likely the students might not have encountered these ideas. Although more and more schools are seeing the value of teaching some aspects of atomic structure in KS3 it is not in the national curriculum as it currently stands. This might make teachers reluctant to include these questions, they might be worried that students will lose motivation and feel frustrated by their lack of success. This is where things get interesting. There is some evidence that pre-testing students on basic knowledge they are about to encounter has a beneficial effect. Peps shared a good summary of the evidence in a tweet.

Can pre-questioning or pretesting be useful for learning?

🎓Short summary of a 2023 review by Pan & Carpenter ⤵️

What they did
The researchers explored the literature on pre-testing, which basically means testing students on stuff before you teach it.

What they found… pic.twitter.com/FzdPesU4fa

— Peps (@PepsMccrea) April 24, 2024

This suggests that even if the students are unsuccessful the quizzing will identify the key information needed and prime them to assimilate it more successfully. In Mr T’s case, if he is unsure if the students will be able to answer the question then given the evidence above, it’s probably better for him to ask the question rather than not. Because Mr T has chose mini-whiteboards the stakes of the assessment are already low due to the lack of permanence and because he uses a ‘show me’ routine the stakes are lowered even more because answers are shielded until all are shown so less embarrassment occurs for a wrong answer. 

Overestimation of the teachers knowledge of student understanding

This is very common. It’s also very unsurprising. Humans are poor judges of other peoples understanding and experience. Think of all the cognitive biases that can hinder this, from confirmation bias to expertise blindness there are multiple mechanisms that would lead a teacher to think students had a better understanding or memory of past events than they actually do. Watching lessons you often token activation of prior knowledge phrases like ‘you’ll remember in year 8 we looked at atoms and elements’. We often fall into the assumption that students will retain these experiences, but often they don’t. However they know the demand characteristics of the question and often dutifully nod along. 

Implementation advice.

Because my job is now mainly focussed on supporting teachers and leaders to implement change I thought I would finish this blog with a few suggestions on how to frame these ideas to make them easier to implement for teachers. This assumes you have read my blogs on CPD and the overall structure of sessions. 

1. Planning backwards the prior knowledge needed for a lesson. Great to do in pairs or threes. Often teachers will focus solely on the declarative knowledge and ignore the procedural knowledge. For example in distance time graphs they will think about all the speed knowledge but not the fundamental graphing knowledge the students need. A lot of subjects find the demarcation between the types of knowledge harder to define and sometimes curriculums are imperfect and there is no clear prior knowledge. In these cases I learnt from Adam Boxer that we can sometimes check prior experiences, especially ones that might form part of our analogies or exemplification.
2. Framing questions. How can we make sure our questions are framed to ensure swift, but informative answers? How can we scaffold for the weakest students? Often this involves frontloading the information in the question similarly to how retrieval practice questions are written. For example, the question is the definition and the answer is the keyword.
3. Frame the choice of questions around the curiosity of the teacher. Instead of making a fixed rule on the number of questions or the level of detail that must be required just ask the teachers to consider what they are curious to find out what their students already know. This mindset gives teachers the autonomy and freedom to experiment in their practice and provides a good starting point for follow up discussions later on.
4. Self-correction cues. When teachers find themselves saying “remember when” tell them that is the time to initiate the check for prior knowledge. Adapt teaching and planning resources to include nudges, possibly by pre-planning prior knowledge check questions into slides or schemes of work.

Further reading

Here are some other blogs that have mentioned prior knowledge checking that I have found useful.

If you want a science scheme of work that explicitly identifies prior knowledge and suggests questions then check out Springboard KS3

The power of pre-requisite knowledge

Claudia Allan has a great set of blogs on this topic on their website. 

Prereq Checks – do they know what they need to know and how do we know?

So they don’t get the prereq check. Now what?

But I did a prereq check!