The Conversation
Almost as soon as the COVID-19 pandemic began, graphs and many other visualisations charting the rise of the virus started to multiply. Many show the cumulative number of deaths attributed to the virus. This number, of course, will always rise, but will also – eventually – plateau. A cumulative total can never fall.
Other published graphs have shown the number of deaths reported each day for various countries. These are more useful, but the reader is still left trying to discern the extent to which the rise from one day to the next is larger or smaller.
The graph below is different. It shows both the number of deaths each day and the rate of change in that number. Most importantly, it uses smoothed data – a moving average from the day before to the day after each date shown. This method of showing change is explored in my forthcoming book, Slowdown, which I worked on with illustrator Kirsten McClure who turned my crude Excel graphs into clearer visuals. It’s a useful way to look at data when it is change that is of the greatest interest.
