Practical work, problem solving and formative assessment
When carrying out practical work, inevitably there will be some equipment that “does not work”. This can be a major problem for the teacher, as students get frustrated that they cannot get their experiment to work and they want you as the teacher to sort it out for them. Of course, even if you have just three or four groups with problems, it can severely disrupt the flow of the lesson if you are having to sort it all out yourself.
There are a few stages to addressing this issue: preparation of the equipment; students’ clear understanding of the practical procedure, theory and outputs; and, most crucially, a mind-set of problem solving, where reliance on teacher input is almost a last resort.
Preparation of the equipment
In many cases, the reason that a practical is “not working” is due to an error in the set-up or understanding of the students. However, particularly with electrical circuits, faulty equipment can be the stumbling block. In this step, your teacher and technician colleagues are key. During a practical lesson, any faulty equipment (e.g. flat battery, faulty wire, blown bulb) should be removed and set aside in a different place – not thrown back into the same box at the end of a lesson, causing the same problem for the next group. This links to the problem solving mind-set – as students understand the importance of identifying and removing faulty equipment in their practical set-up, this will help all students and teachers using the same equipment across the school.
Practical procedure, theory and outputs
Before commencing the practical, students should be able to describe what they are going to measure, and how they are going to measure it. In many cases, they should also be able to say why they are carrying out the practical, but sometimes this understanding will come during or after the practical work has been carried out. In the case of our work with electrical circuits, drawing out the circuit diagram and being able to describe the expected behaviour of the circuit will not only mitigate problems when using the real circuit components but it will also allow formative assessment of the students understanding of the procedure and circuit theory. Teachers can ask students to describe each part of the circuit they have drawn and how the components will work together. This can help to identify gaps in their knowledge or misconceptions.
A mind-set of problem solving
An expectation that a practical set-up will work straight “out of the box”, or piece of computer code will work first-time, or a tricky mathematics problem will be solved on the first attempt is not good preparation for the real world of STEM careers. Failure is often key to success – James Dyson made 5,126 versions of his vacuum cleaner before finding the one that worked and started off a multi-billion pound company.
Students should try to identify why their set-up is not working as expected, first working with peers in their own group and then checking with other groups. Collaboration between groups can be encouraged to ensure the best outcomes for all – copying the experimental set-up is OK, as long as they understand what they have copied and how it may differ from their first attempt.
This mind-set is important when dealing with electrical circuits. In the next step we will look at an example of an alternative teaching plan for when things go wrong. In the next activity we look at how problems can be changed into assessment opportunities.
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