Visualising expert estimates of covid-19 transmission by Will Stahl-Timmins

In the early stages of the covid-19 pandemic, there were confusing and conflicting messages about how best to keep transmission rates down in public places. Should we wash our hands? Wear a mask, and/or a visor? What if we were outside? Talking loudly? Singing? No clear evidence about the most effective ways to reduce our risks were available. The traditional way of presenting point estimates and error bars didn’t seem appropriate but the information, however uncertain, was important to know to protect ourselves and others. We created this interactive visualisation tool to help people understand the likelihood of covid-19 transmission in different situations. It was created as part of a 13 month long collaborative project between scientific experts from a UK government advisory group (SAGE), and a multimedia team at The BMJ (British Medical Journal). The many thousands of data points in underpinning the graphic were collected from 27 experts via a knowledge elicitation study. This was a more involved and resource-intensive project than we can usually justify, but the extraordinary circumstances of the covid-19 pandemic and the need to convey accurate information to an uneasy public made it well worth the extra investment by The BMJ and author teams. It remains our most accessed interactive graphic on initial publication to this day, with nearly 100,000 visitors in the first month.