The problem with perfection

Trying to replicate lab-based learning online? Remember to chuck in some randomness, says Dr Rachel Martins

With the many challenges of online teaching that we have become familiar over the past year – from spotty connections to a lack of access to physical resources – you might imagine that something going perfectly would be welcome. Ordinarily, it would, but in the case of simulated laboratory physics, the loss of the real-world randomness removes valuable learning opportunities.

Teaching physics in the lab is a fundamental part of a student’s science education. It provides an opportunity to witness concepts in action, develop practical skills, and, crucially, to make and learn from mistakes. The physical world is complex, and students have to contend with randomness and errors from unexpected sources. Electrical experiments, for instance, often involve changes due to heating and lost voltage.

Designing, running and suggesting improvements to an experiment is a vital part of the curriculum, honing a student’s observational skills, critical thinking and understanding of the underlying concepts.

In the move online during the pandemic, we adopted virtual alternatives but there was no randomness in these pre-programmed environments. Although we had used these simulations as a teaching tool for years, using them for summative assessments was a unique challenge.

The experiments completed perfectly every time, with no ambiguity in measurements, delivering precisely linear results exactly as the underlying principles dictate. I was faced with the challenge of assessing students’ understanding of uncertainty, errors, and ability to improve an experiment, in a perfect online environment.

In the future of teaching and assessment, I believe that there is a place for the virtual lab, especially as it evolves beyond its current, overly perfect state

Randomness intro

I redesigned the assessment briefs and mark scheme to ensure that they still met the same criteria as real-life lab work for the universities I work with. I then set to work explaining it to the students. This included asking them to sign a learner declaration and embed that into their report. They had to declare everything they submitted was all their own work. It was a good opportunity to teach them about the dangers of plagiarism with a focus on the rules.

Following that, I introduced random and systematic errors to the data so that students had to draw a line of best fit. This also ensured that the trend line didn’t pass straight through the origin. As well as requiring them to apply their graphing skills, these changes gave the students a chance to evaluate where systematic error might come from.

Similarly, I allowed students to choose whether to read the gradient of their trend line the old-fashioned way – using grid lines – or with Excel’s digital alternative. Physicists take advantage of IT tools in real lab work and knowing how to do so has value. I approximated students’ ability to make precise readings by sending them a photograph of a micrometer screw gauge and their ‘practical skills’ by reviewing the adjustments they made to the methodology and how they justified them.

Larger lessons in digital learning

While hardly ideal, our virtual lab work was largely successful. Feedback I collected from students was positive, and they valued the accuracy that the simulations provided, even with the added randomness.

I don’t believe that the hands-on experience of conducting an experiment in a lab will ever be fully replicated in a virtual environment. Specifically, the ability to make mistakes and introduce other systematic errors is unique to the real world. However, I’m certain that the gap between real and virtual will close, and I look forward to advances in lab simulations.

Virtual labs also introduce the opportunity to see more of the physical world. For our simple harmonic motion experiments, students were free to break free of Earth’s 9.81m/s² of gravity and understand how their experiment differs on other planets.

In the future of teaching and assessment, I believe that there is a place for the virtual lab, especially as it evolves beyond its current, overly perfect state.

There is significant potential in them: they are accessible and inclusive alternatives for students who cannot participate in hands-on experimentation. This will become increasingly important in the future as more students choose to study in their home countries, purely online.

 Dr Rachel Martins is a maths and physics lecturer at Leeds International Study Centre at the University of Leeds

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