Should you be Doing that Practical?
Practical work is an important yet contentious issue in Physics teaching. Too often a practical lesson is packed full of things in a short space of time. Students are expected to come in and get settled, go through the practical method, get ready for the practical, get the equipment, set it up, do the practical and gather data, pack away, draw a graph, analyse results, conclude… it’s exhausting and chaotic, and you will only have about one hour to do all of this.
This article is about getting you to consider a practical activity carefully, to question the purpose of the practical and how it will be conducted, and to consider alternatives which may lead to more successful student learning.
The Gatsby benchmarks
The Gatsby Charitable Foundation wrote a guide in 2017 to Good Practical Science in which they outline 10 benchmarks for educators. You can read the full report here. Alternative STEM Learning has a good summary here with recommendations for each benchmark. The benchmarks are:
|1 PLANNED PRACTICAL SCIENCE||Every school should have a written policy that explains why teachers use practical science, the outcomes they expect from it and how they achieve those outcomes. The process of producing the policy is as important as the policy itself.|
|2 PURPOSEFUL PRACTICAL SCIENCE||Teachers should know the purpose of any practical science activity, and it should be planned and executed so it is effective and integrated with other science learning.|
|3 EXPERT TEACHERS||Teachers should have subject-specialist training (bothinitial and continuing) in the subject (biology, chemistry, physics etc) and age range they teach, so they can carry out practical science with confidence and knowledge of the underlying principles.|
|4 FREQUENT AND VARIED PRACTICAL SCIENCE||Students should experience a practical activity in at least half of their science lessons. These activities can be short or long, but should be varied in type.|
|5 LABORATORY FACILITIES AND EQUIPMENT||Schools should have enough laboratories to make it possible for every teacher to do frequent practical science safely. Each laboratory should have sufficient equipment for students to work in small groups.|
|6 TECHNICAL SUPPORT||Science departments should have enough technical or technician support to enable teachers to carry out frequent and effective practical science.|
|7 REAL EXPERIMENTS, VIRTUAL ENHANCEMENTS||Teachers should use digital technologies to support and enhance practical experience, but not to replace it.|
|8 INVESTIGATIVE PROJECTS||Students should have opportunities to do open-ended and extended investigative projects.|
|9 A BALANCED APPROACH TO RISK||Students’ experience of practical science should not be restricted by unnecessary risk aversion.|
|10 ASSESSMENT FIT FOR PURPOSE||Assessment of students’ work in science should include assessment of their practical knowledge, skills and behaviours. This applies to both formative and summative assessment.|
It is a report worth reading all the way through and one that will help you guide your thinking for when it comes to planning a curriculum or for individual units of work.
In this article I would like to draw attention to the second benchmark which is “purposeful practical science”.
When planning for a practical activity in a lesson, aside from the obvious and absolute essentials like considering health & safety and taking your specific class and students into account on your risk assessment, I would also recommend considering the following points.
Do the students need to be doing this practical themselves?
Many times teachers will do a practical activity simply because it’s on the scheme of work, or because the students haven’t done a practical for a few lessons. A scheme of work is not a manual, and frequency of student practicals is not something I believe needs to be taken into account (note that Gatsby’s 4th benchmark refers to frequent practicals, but this can also include teacher demonstrations).
A practical might be better as a teacher demonstration instead, or as a video or online simulation (check out PhET), for many reasons.
Consider these questions:
- Is there enough practical equipment available for all students to be able to work successfully? You don’t want to be in a situation where students have to work in large groups.
- Are there certain risks involved which you would rather eliminate by not having the students involved in the practical itself? This is a point that needs serious consideration. If you are a UK educator then you are no doubt familiar with the CLEAPSS guides.
- Is the practical procedure too complex for students to successfully complete within a lesson? Consider splitting it across multiple lessons if possible.
- Are there multiple things that you want the students to test in the one practical? For example when investigating insulation around a beaker of water, the students could either vary the number of layers or the type of insulation, but they probably won’t be able to do both in one lesson to a high standard. You could split the practical between groups, where each group just does one version of it well, allowing them to take repeats and then sharing their results with the rest of the class on the board perhaps.
Will the practical hinder learning?
Think about a practical that you would usually do with one of your classes and carefully consider if it is 100% sure to guarantee that the students are learning what you want them to learn from it. Let’s take a practical like finding the current in series and in parallel circuits. If this practical is done as an inquiry practical, you will expect the students to find that the current is the same at different points in a series circuit, but that the sum of the current in each branch of a parallel circuit is the same as the current going in or out of that branch. Straightforward enough.
But even if you do this practical yourself there will always be a chance that the results don’t match up quite as perfectly as you’d want. Suddenly the students are learning “rules” which are incorrect. For some great tips on electricity practicals I highly recommend Robert Pritchard’s article in TES Magazine (Four ways to avoid shocking electricity lessons).
Consider these questions:
- What misconceptions might this practical introduce if not done correctly?
- Do they have enough prior knowledge to know what they are looking for in this practical? Have I done enough theory before this practical for the students to understand what they are looking for?
- Could I just tell them the outcome of the practical instead? Personally I would not get my students to discover the series and parallel rules as more often than not, they will not get the perfect data needed to show these rules. Any deviation from perfect in this example and the students will not learn what you want them to learn.
What are you looking for in the practical?
If you are going to do a practical activity then you need to know specifically what it is you are going to be looking for during the task. Are you seeing how well your students understand their control variables and do so successfully? Are you seeing if students can pick out the correct equipment for the task? Are you seeing if students can successfully set up a complete circuit?
If, however, you’re assessing their graphing, mathematical or analysis skills, then why not just get to the point and assess that without the practical? Question if there really is a need for them to gather their own data first. If you want to assess certain skills at A Level then I would recommend this brilliant A Level Physics Practicals resource (big thanks to Chris Baker for bringing this to my attention).
Think about which skills you are going to be assessing in this practical, and whether the students have already practised that skill recently. For example I wouldn’t get the students to draw a graph of their results every time I do a practical, but I would like to know when the last time they did draw a graph so I can know if they should be practising this skill again. You could keep a checklist for the class with the type of skill, and which date they last showed you each skill. This is a requirement for the A Level course anyway, so why not introduce it to lower year groups as well.
Consider these questions:
- Which skills am I looking for in this practical and can they be assessed another way?
- What exactly am I assessing my students on during this practical?
- What data do I want them to be collecting during this practical, and is gathering data even necessary for this practical?
- Do they need to draw a graph at the end of it for analysis, or consider uncertainties, accuracy or resolution of their measuring instruments during the practical?
- Am I asking too much of them in one practical and can this be mitigated somehow?
- What are the students going to do after the practical has finished?
What problems might arise?
Some practicals have a lot of equipment involved. While this isn’t a huge issue in Physics, there are still some special pieces of lab equipment that a student may be inexperienced in using. When finding the density of a small irregular object for example, students need to be able to know how to use a top pan balance and a measuring cylinder (or a eureka can). If this is the first practical that they are seeing these pieces of equipment then this equipment needs to be the focus of the practical. If you just want them to use a new piece of equipment then focus on that and give them a graph of your data to analyse.
If it’s a fiddly practical but the analysis is interesting then demo it for the students and give them the data to draw a graph so you can test that part instead.
Also think about how the students will be using the equipment and what potential issues that might arise during the practical. The best way to do this is to make sure you do the practical yourself first.
Consider these questions:
- Do the students know how to use all of the equipment they need to successfully complete this practical?
- If you’re introducing new pieces of equipment, how many are you introducing?
- What problems do you anticipate coming up during this practical?
Considering these questions will make for a more enjoyable and worthwhile practical experience for you and your students. Of course do practical work, but think about why you are doing it and what you want to achieve from it. Practical work in Physics is important and should be conducted, but do consider the point of your practical activity and whether the point can be better made in a different way.
Good Practical Science by The Gatsby Charitable Foundation, 2017 https://www.gatsby.org.uk/uploads/education/reports/pdf/good-practical-science-report.pdf
Four ways to avoid shocking electricity lessons https://www.tes.com/news/four-ways-avoid-shocking-electricity-lessons-GCSE-physics
Practical Physics on the IOP website https://spark.iop.org/practical-physics