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Published: Friday, August 16, 2019

No pain, no gain - looking beyond CPAC with practical work

 Jon Hale, Head of Biology at Beaulieu Convent School explores ideas for enhancing practicals:
 
From the little conversations I have with fellow Biology teachers in the UK, many schools are doing more practical work than 5 years ago (pre-reform), but little more than they have to in order for their students to fulfil the Common Practical Assessment Criteria and achieve their Practical Endorsement. The exception to this anecdotal evidence describes students taking their practical records with them to university interviews as they show off the wealth of experiences. 
 

There are loads of excuses that teachers can use to explain why their students do not get the perfect experience of practical work. The sheer volume of content is never going to go away, the cost of specialist equipment such as a thermocycler or even the timescales involved in certain investigation like genetic crosses of Drosophilia. So what we choose to pursue needs to be invaluable to the students learning and high impact towards improving their attainment. 

 

@STEMLearningUK shared an evaluation tool in the @FutureLearn Teaching Practical Science: Biology course that was incredibly comprehensive and well worth a look at completing once or twice within a cohort, especially if things didn’t go according to plan. When we are focused solely on meeting the Common Practical Assessment Criteria (CPACs), we often lose sight of the progress students need to make before developing competency in a particular technique. Or try to eek out every potential assessment objective from a practical to justify the 'time lost' to the PAG without considering the cognitive load on the adolescent human. 

 

Recently I have been playing with ChemixLab to make some A level integrated instructions. At the moment the new version is still in beta but it is looking good so far helping students understand some of the nuances of a particular protocol, such as judging colour changes, etc that get lost in words. The feedback from the students, especially those who do find it difficult to process information, has been positive so I might be making a concerted effort to do a few more in the near future. 

 

However the biggest change in my own practice has been to revert to how I want students to experience phenomena rather than complete a set of data. For example, rather than just doing enough to meet the CPAC for enzyme-dependent reactions with the classic amylose and amylase, we explore the entire topic through practicals. We start with the identification that liver, apple, potato, bacteria and yeast all contain catalase and start trying to make some kind of comparative investigation. This allows standard deviation to be embedded early in Year 12s as a bonus, but the focus is on the idea that enzymes might be different due to genetic differences or could be being expressed at different levels within the organisms. There is a lot to discuss regarding the quality of the data too, so although the practical demand is low (GCSE level), the ability to question 'why?' to everything is instilled.

 

Then it is onto the concentration of bacterial catalase (serial dilution opportunities galore through this topic), the concentration of hydrogen peroxide, temperature, pH and lastly the concentration of copper sulfate to discuss inhibition. At every point the students are driving the experimental design as a result of their previous learning. With the experiments being quick to run it gives the opportunity for them to discuss or research the reasons behind the data.

 

Sometimes the students complain about the volume of work that they feel that they have to undertake in order to complete the practical, but this is quickly forgotten when they consider what they have learnt as a consequence. No pain, no gain. 

 

I do like quick practicals, like looking at prepared slides when studying the pancreas, and having students get into the habit of producing biological drawing everytime. It doesn’t take long for them to know exactly what is required when it comes to those Indirectly Assessed Practical Skills in their examinations, whilst also practising their magnification calculations to that level of fluency I look for. With the release of legacy specification controlled assessments, there are now a whole host of quick practicals for most elements of the specification. 

 

Sometimes it is nice to do an experiment where you won’t know what will happen. Whilst in a microbiology lab session at the University of Birmingham (STEM Insight placement, I can’t sell this opportunity enough!) I was able to observe a review lesson, with the undergraduates looking at a myriad of plates to make their conclusions. The one experiment that was the take home one for me was using Warcop’s media to grow fungi from leaves and soils. As soon as I was back in the classroom, the students were investigating the unseen biome and within a week, the invisible was visible and the hook for plant defences was made. 

 

The Microbiology Society and the Microbiology in Schools Advisory Committee have loads of really cool practical opportunities that allow a little more exploration that the standard microbiological techniques like measuring the pH change in yoghurt. Have a play and maybe find your own spark.

 

Science and Plants for Schools (SAPS) are currently running a FutureLearn course with a few plant based practicals ranging from osmosis and respiration to vegetative propagation over the three weeks. SAPS are very good at producing a range of alternative procedures and extension tasks that support the full spectrum of A level Biologists. 

 

Ecological sampling is one of those topics rushed before the exams or used as filler in the summer term, but does it have to be? In Jersey, it is always sunny (the TV tells me so) so everyday has the potential for fieldwork, yet we don’t do enough. I would love to go out and study the rocky shore under the full moon but I also value my free time!

 

Fieldwork is one of those tasks that for many is a tick boxing venture rather than the immersive experience it can be. When I was little, my dad took me and my brother off into the Sperrins in Northern Ireland to look for freshwater pearl mussels. Spending a day, walking in rivers looking for brown things, that was fun for me and I am not even sure why, maybe I am just easily pleased. Ecology shouldn’t be a chore but a treat. Traipsing across the dunes on a succession study always stimulates me to talk about reindeer moss and the Telemark heroes; Sphagnum moss and its special properties. Anecdotal, irrelevant but maybe it helps with Science Capital and stimulates a little interest in something they can share with their families. 

 

Undoubtedly there are lots of practicals that we’d like to do, but the necessary equipment unjustifiably expensive.

 

Gene technologies for example. Thermocyclers are not cheap, but there are a few cheaper options out there, like the miniPCR or FelesB that might be worth the shipping from the States. I saw recently that someone had donated a thermocycler as a museum piece at an airport, so sad. However, there are options to fund projects, like The Royal Society Partnership Grants, where if you are successful in applying, they will give you up to £3000 towards equipment and consumables. 

 

Like every lesson, planning a good practical experience has to start with 'why am I doing this?' Like many Biology teachers, I actually enjoy Biology both aesthetically and down to the complexity of the subject and sometimes that is enough of a reason for a practical, like actually seeing the lignin spirals from tinned rhubarb, or sticking your fingers in a bull’s heart.

 

Sometimes students need to see that actual enjoyment on our faces to understand that Biology is an amazing subject to explore with their own eyes.