Explaining with comparison

 A timely article on the website engineering.com is an excellent example of a way to explain a complicated idea to a non-specialist audience: How One Virologist is Using Cheese to Explain Covid-19. The title itself caught my attention, and I challenged my students to think of ways that cheese could be used this way before reading the article (they couldn't, but neither could I). 

Link to article: https://www.engineering.com/story/how-one-virologist-is-using-cheese-to-explain-covid-19

In this blog, I've referred to using examples in texts to raise students' awareness of how to focus on audience when they write or present. One of the ways to explain a concept is to use comparisons to something the audience already knows. In this article, the comparison uses the example of stacked slices of Swiss cheese (a cheese with holes).

The article relates an idea of Ian M. Mackay, a virologist at the University of Queensland, who uses the example of Swiss cheese to explain why one defense alone against the Covid-19 virus is not effective, but that a variety of methods are:

    "Imagine multiple Swiss cheese slices with their holes and all, each lined up one after the other. When the cheese is stacked, it is hard to see what's on the other side. However, when you take some slices out of the stack, it becomes more visible. When applying this analogy to the COVID-19 pandemic, the layers can signify social distancing, masks, hand-washing, refraining from touching your face, avoiding crowded areas, testing and tracing, ventilation, government messaging, quarantines, and vaccines."

The infographic above shows the idea, and is from Mackay's twitter account (pic.twitter.com/nNwLWZTWOL).

As stated in the article, "The model aims to explain that there is no single intervention that can be the answer to solve the virus, as each layer has its holes or faults. Instead, society should adopt multiple methods to stop transmission of the virus."

The idea is related to the Swiss Cheese Model of Accident Causation, which comes from psychologist James T. Reason (in his book Human Error) and is said to "explain many disasters from the space shuttle Challenger Shuttle (sic) explosion to the Bhopal disaster, and the Chernobyl nuclear accident." In Reason's model, the slices of cheese are lined up so that the holes are in a straight line, leading to the buildup of the accident. The article has an image of Reason's model as well.

Engineering students can use the examples in this article to think of their own ways to explain a technical concept from their studies or work to a layperson. Particularly useful is the concept of analogy, which many of my students often have a difficult time understanding. Not only is there the analogy of aligned slices of Swiss cheese to explain how multiple actions provide a better defense against the virus, but there is also a quote from James T. Reason giving an analogy that compares active failures to mosquitoes:

    "Active failures are like mosquitoes. They can be swatted one by one, but they will still keep coming. The best remedies are to create more effective defenses and to drain the swamps in which they breed. The swamps, in this case, are the ever-present latent conditions."

The explanations themselves provide a template for students' writing or presentations:

• Imagine ____
• When applying this analogy to ____
• the ____ can signify ____
• ____ are like ____
• The ____, in this case, are ____

The article ends with: "This model is not widely accepted without its share of criticism due to its limitations in understanding the full scope of the pandemic; however, it can guide society toward a better understanding of the risks and tools to combat the virus in these unprecedented times."

In the same way, this example alone might not be enough to help students come up with their own ideas; however, it can guide them toward a better understanding of how comparisons can be used to explain technical information to a non-technical audience.

A Bonus: Students can listen to the article being read by a male voice with an American accent by clicking Listen to Story at the top of the page. The recording is 5:21 minutes.