Applying Cognitive Science Principles to Practical Work

I’ve been on a bit of a journey with practical work. When I trained to be a teacher I was told that students would remember things discovered for themselves better than they would remember things told to them. Alongside this falsehood I was also told that students couldn’t be expected to listen to me talk any longer than 5 minutes in a lesson, so I should plan a practical so that I could stop teaching talking and get them “doing something”. Finally, and most wonderfully of course, practical work ticked the elusive “K” box for kineaestic learners who were normally so difficult to cater for. Taken together these reasons led me, during training, to look for practical tasks for students to perform in as many lessons as possible and this was reenforced by largely positive feedback from my observers when I did this.

Jumping forward a couple of years and I absolutely hated practical work. My personal reflections (at the end of assessment blocks, terms and years of work) led me to realise that students had learned little during practical work. Students weren’t able to complete tasks correctly without explicit guidance, many didn’t engage properly in practical work and behaviour management was so much more difficult when every student was out of their seat. As a result, practical work was frequently incomplete, students weren’t thinking about the things I wanted them to think about and were sometimes “discovering” and remembering incorrect things because they were doing the practical work incorrectly. Most frequently though, even when I’d improved my behaviour management and written clear explicit instructions in duplicate on powerpoint and worksheets for students to follow, students were remembering the process or events of the lessons, rather than the scientific ideas that I wanted them to think about. In short, they weren’t learning what I wanted them to learn.  I despised practical work and started to ditch many practicals from my lessons.

However, in the last couple of years I’ve come back to practicals and have perhaps found a happy middle ground. Getting involved in twitter, discovering ResearchEd and #CogSciSci has led me to apply some of the principles of Cognitive Science to Science practicals to make them more effective. Slowly but surely, I’ve reintroduced more practicals back into my classroom in a way that is reasonably effective in getting kids to learn.

So here are those Cognitive Science principles (there’s only two really) and how they can be applied to practical work in Science lessons.

Cognitive Science Principle 1: Students remember what they think about.

Or as Dan Willingham but it so beautifully in “Why Don’t Student’s Like School?” Memory is the residue of thought. So…

  1. Ditch attention grabbers and competitions.

Craig Barton has his Swiss Roll story. Bob Pritchard has his flaming tampons. I have my horrific water-pistols lesson. Almost every teacher can tell you of a lesson hook gone wrong.  A lesson hook which became the focus of students attention, the thing they remembered instead of the lesson ojectives you were hoping to hang off the hook.

Science Practicals often seem to be the subject of a “hook” that will grab students attention and make the activity more engaging and relevant for students. I used to run the KS3 chromatography lesson as a “who committed the crime lesson” black pens had been collected from four suspects and compared to ink found at the scene. Next lesson I asked students to answer a chromatography question to which one student said “That’s the Headmaster’s pen, I remember he did it!” I once asked students to choreograph different types of chemical reactions though the medium of interpretive dance only for students to later tell me they remembered Josh getting the moves wrong and ruining their performance. Unsurprisingly when I asked students enagage in a competition of home-made water pistols, they did not remember the salient facts of water pressure, instead they remembered they subsequent chaos.  These attention grabbing hooks are well meant, and might lead to temporary enagement in lessons, but do not lead to students learning what we want them to, because they are thinking about the hook or competition instead. So use these with extreme caution, if at all.

  1. Minimise discovery learning.

Given students will remember what they think about, they are no more likely to remember something that they have discovered for themselves as they are to remember something told to them, as long as they are thinking about the right things. In fact, students will often make incorrect discoveries during practical work which they then remember. When students investigate current in a series circuit, students will move the ammeter around and often find the digital ammeters give differences of a hundreth of an amp or so in different positions. Whilst this can be a great opportunity for discussion on accuracy of measurements, random errors and anomalies, this is only possible if students are already familiar with the knowledge that current should be the same everywhere. If students do not already have this knowledge and are discovering this fundamental law of electrical current for themselves they will often believe that the current slowly leaks from the circuit as they have seen with their own eyes the current drop by 0.02A around the circuit.

As a general rule, I now normally teach concepts before practicals on the same subject. I reserve discovery learning for practicals, which I know from experience, are difficult for students to get wrong (e.g. stearic acid cooling curve) or which give immediate feedback they they’re doing it wrong (perhaps by using visualised instructions – see below).  However, these situations are rare, as immediate feedback (the type built into computer games that kids “discover for themselves”) is only really possible for students to identify for themselves if students know what to expect.  I can’t stand on everyone’s shoulder all the time – or can I? – See Point 5 on slow practicals, below.

  1. Make practical work hypothesis-driven.

Real science, done by real scientists in the real world is not done blindly. As I’ve written about previously, real science is hypothesis-driven. Scientists do not conduct an experiment with no idea of the outcome, they use their expertise in a subject area to hypothesise a phenomenon then carefully conduct an experiment to rule out alternative explanations (the null-hypothesis). Are your students able to predict what will happen during a practical before they start?  If they can’t predict the outcome of practical work, then in most cases I’d suggest they are probably not ready to complete the work.

Whilst it might be difficult for our novice students to fully comprehend the work they’re about to do and think it through to it’s logical conclusion, if we truly want students to act like real scientists then we will ask them to at least try and think things through before starting, having taught them the prerequisit knowledge before hand. If necessary we can use techniques such as 2-part MCQ (example below, and in previous blog) to guide students and assess whether they are ready to engage in practical work. By asking students to hypothesise the outcome we have already directed their thinking towards the key concept of the work and this remains front and centre of their thinking throughout.  Below is a hinge-point slide in my work on Enzymes. Only when students can successfully answer both parts of this question, do I know that they are ready to test their hypothesis…

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  1. Use Narrative tools such as “conflict”, “complications” and “causality”.

I’ve written and spoken previously about harnessing the priviledged nature of stories in science teaching and the oral teaching tradition, which is particularly useful in non-practical lessons, however it can be used to engage students to think about the key concepts in a practical lesson too. During a practical demonstration it is often useful to stop and ask students “What happens next?” Then perhaps send students away to reconstruct the demo up to that point themselves and complete it, all the while thinking about “what will happen next?”  Similarly, during the electrolysis of solutions practical, I like to demonstrate the practical using a Copper Sulfate solution, talking the class through what is happening. Then I ask them to predict what would be different if we changed the solution to one containing Sodium Sulfate?  Take some answers from the class (hypotheses) and then send them away to do this second half of the practical themselves with the key question for the lesson at the forefront of their minds as it is the “conflict” in the story of the lesson so far.

 

Cognitive Science Principle 2: Students have a limited working memory (a.k.a. Cognitive Load Theory).

Adam Boxer has written wonderfully and extensively on this in the past and I often have his diagram (below) in mind when I’m considering practical work and how I can minimise student’s cognitive load during practical work.

Picture1

  1. Use slow practicals to minimise cognitive demand.

Again, Adam has already written extensively about this, but I’ve found in particular this approach is most useful with young KS3 students for whom much of the equipment is new. By breaking tasks up into very small steps and bringing the class back together, either silently at their desks, or collectively at the demonstration bench allows the students have easily completed each task without cognitive overload. It allows the teacher to check each step is complete (immediate feedback), and allows extensive questioning at key steps by the teacher of the class to guide the thinking of students on the key elements of the task at the important moments “look at the thermometer now that the water is boiling, what do you see?”  Whilst it can seem like the lesson is moving slower than usual, it isn’t really, and it’s certainly moving more efficiently than usual with more of the class completing the task successfully.

  1. Use visualised instructions to lower cognitive demand and provide immediate feedback.

Visualised instructions effectively use dual coding to guide students through complicated practical tasks with both written instructions and diagrams to allow students to easily set up practical equipment and complete steps in the correct order. Personally I’ve found these to be most effective with older KS4 students who are already familiar with most of the equipment being used and just need to make sure they complete the steps in the right order. A number of science teachers have been making useful visualised instructions that we can all use, including Adam Boxer, Dave Paterson and John Lindney the latter two have made visualised instructions for all the KS4 compulsory practicals.  The use of these instructions help students minimise the amount of working memory dedicated to the process of completing the task, and allows students to free up working memory, through our guidance and questioning to think about the scientific concepts involved, not just the process the practical.  When combined with techniques above such as hypothesis driven tasks, students spend more time thinking about the things we want them to think about during the practical, and less time wondering if they should pour the solution into a beaker or an evaporating basin, or indeed what the difference is between a beaker and an evoporating basin.

 

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When planning practical lessons we should consider what students are thinking about, how we can direct their thinking towards what we want them to think about and how to minimise the information that we don’t want them to think about. By doing these things we can make practical work effective for students. BUT… and it’s a big “BUT”… there will still be times when students will learn more effectively without practical work.  We should always be willing to consider during our planning if there is an alternative task which will allow students to think about the scientific concept more clearly and without distraction? For example will students learn the complicated voltage-current relationship of a filament bulb most effectively from a tricky to complete practical, or from plotting model data given to them, followed by SLOP questions?  Sometimes, despite the approaches above, it’s still best to avoid practicals and go for something else.

 

This is a blog version of a talk that I gave at the ASE West of England Conference at Bath Spa in November 2019.

 

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