5 Simple Steps for Higher Impact Practical Work
1. Use a pre-lab activity to set the scene
In order to ensure the students get the most out of a practical session, they need to be 'primed' for learning. This happens when they have tried to solve a problem themselves first; they have attempted to generate the learning themselves. According to Roediger and McDaniel in Make It Stick this is because during the process of generation, the student strengthens the route to the gap in their learning that the practical will shortly fill. This can take a number of forms:
Making predictions about what will be observed. For example, in an activity on the reactivity series, students could be asked to predict all of the observations they will make before completing the RSC Microscale practical on displacement reactions. This forces them to engage with why the observations they make take place.
Setting up the student for a 'crucial experiment' situation. In my blog post on crucial experiments, I discussed setting up tasks so that the crucial experiment with a prep-lab activity leading the student to compare two different theories about what they will observe which is then followed by a practical which allows the student to select between two theories. This could be done using a concept cartoon, in which the students evaluate the two competing theories before they complete the practical. For more details about using crucial experiments to engage students in practical work, see the full blog here.
Recall of background knowledge which will be required to complete the practical. This ensures that all of the concepts that the student will require are bought into the students' short term memory for use during the practical task. This could be how to make a standard solution, why there is a difference in the solubility of halogens in cyclohexane and water, or identifying hazards in the practical.
2. Photo strip or cartooning the stages
Students have a tendency to complete practical work and believe that doing the practical really helped them understand the theory, and then promptly forget how to actually do the practical! This is particularly true when I'm teaching the section on making salts to Year 10 students in which they have to remember all of the stages for the insoluble base method, titration and precipitation. One way I have used to good effect to help students to remember all of the practical steps, it for them to take a photo of each step which is worth a mark in the IGCSE paper. For example, for the insoluble base method they would take a photo of: adding the insoluble base (1), until excess base remains (2), filtering the mixture (3), heating the filtrate until saturated (4), cooling to form crystals (5) and filtering the crystals and patting dry with a paper towel (6).
If students are not allowed to use their phones in class then cartooning can also work in the same way; students just need to draw simple diagrams themselves. For this they can put the marking points into speech bubbles along with each step. As a starter for the following lesson, students then sequence the steps for their practical method.
If students make a photo or cartoon strip for a number of the different practicals they are covering during the course, an excellent way of adding a bit of 'desirable difficulty' to their recall it to mix up all of their practical stages for different experiment and ask the students to categorise the stages by experiment before they order the cards for each particular practical.
3. Match high quality why and how questions with each step
Sometimes nothing time-consuming to prepare or fancy is required, all a student needs is for their teacher to ask them the right questions at the right times to stretch their understanding. If using this approach to improve students' thinking during practical work, it is important that the questions that are asked are high quality enough to stimulate deep thinking. This will leave students reflecting on the task even when the teacher is not directly talking to them. This means asking the kinds of 'how' and 'why' questions that students can discuss until the teacher comes around the laboratory again to hear their suggestions. The teacher can then feedback and ask follow-up questions. The more time students spend actively thinking about the experiment, the more valuable the time taken to complete it actually is.
If the questions that a teacher asks during a practical task are simple 'what' questions, students can either answer these quickly and then revert to thinking about what they watched on Netflix last night, or do not know the answer at all (so get back to thinking about what they watched on Netflix last night).
This approach can also be resource-led, with a practical worksheet organised with challenging questions about the method, embedded throughout the task. This ensures that all students are thinking about the questions the whole way through the practical task. This may be particularly useful if some students need more support with the practical aspects of the task than other, for example students with dyspraxia who pay struggle to manipulate the apparatus for some experiments. Labdog software is designed to facilitate this approach to teaching practicals if students have access to technology during practical lessons.
4. Making a safety video in class
One of the most successful practical tasks I have ever led in a class, was when students were challenged to make an updated safety video to replace the RSC version. Before the lesson, students had to watch the video about how to complete cracking safely in the laboratory, and then during the lesson they used their iPads in groups of three to make a new video. The reasons why this approach was so successful are given below:
The students were really focused on the hazards which was crucial for carrying out this relatively risky practical with a class of 25.
Students needed to be able to explain clearly what was happening in each step to the camera: this means they were processing the information and synthesising their learning about the practical, embedding their knowledge into their long-term memories.
One word of caution. In this particular group, students were already very familiar with how to use iMovie, so this was not distracting them from the learning about cracking. However, in a class with students who have not used iMovie before, or are relatively inexperienced at making videos, the focus of the learning can easily end up being about video editing rather than the science.*
Overall though, this is a particularly excellent way of improving practical impact if students do have access to the technology, even just their phones, as it does not require any additional teacher preparation at all! Any relatively hazardous experiments benefit from this approach as then students take the risks seriously, allowing us as teachers to focus on the science going on a little more, rather than just on hazard detection and management.
5. Redesign practical tasks to avoid repetitive thoughtless action
Some standard practical tasks are mind-numbingly dull. This is because they require students to stand over a beaker stirring for 30 minutes recording the temperature (determining cooling curves or solubility curves), or measuring the mass or volume of gas every 10 seconds for 5 minutes and then repeating with a different surface area or concentration of acid (rate of reaction between acid and marble chips). These kinds of tasks do not extent students thinking as they are carrying out the same actions on repeat which has no cognitive benefit. I vividly remember being ruthlessly critiqued by my GTP mentor for a lesson where students spent 30 minutes just recording data!
As teachers we should be mindful of setting these kinds of practical tasks and try to find a creative way of reorganising the lesson when there is no reasonable alternative to carrying out one of these practicals. For example, for solubility curves, instead of each pair of students determining the maximum mass that can dissolve in water over a range of temperatures, each pair could look at a specific temperature and then the class could plot the data collaboratively on Google Sheets. Lesson time can then focus on evaluating whether or not their data was reliable, or if it was a fair test. Students make their own concept cartoons to present their ideas. They could also complete a past paper question which used another method of determining the solubility of a salt.
To redesign the lesson on rates, each pair could use a different concentration of hydrochloric acid and then complete the practical three ways, once using a gas syringe, once using a balance, and finally collecting the carbon dioxide over water. Once again the data could be plotted collaboratively to determine the relationship between concentration and rate, but the discussion can then focus on comparing and contrasting the strengths and weaknesses of the different methods leading to much more sophisticated, higher-order thinking from the students.
Chemistry in particular, and science in general, is practical, and teachers should not shy away from practical lessons because they feel that students are not learning as efficiently as they would in a theory lesson. Using some of the steps above will ensure that student are thinking more during their practical work and ensuring that it earns its place and time in the curriculum.
*Any safety videos made in class should not be put into public domains, such as YouTube, as student videos are not authorised safety guidance for other schools and students to follow When using this approach, always use CLEAPSS approved videos as the stimulus material, and use the student video as an opportunity for student-teacher feedback only. Many thanks to Bob Worley for his feedback on an earlier version of this post.