
LettersWith talk of a sixth Covid-19 wave in Hong Kong, can we trust data models?
- Given that different assumptions made by researchers will generate very different projections, claims made by health experts should be accompanied by a disclosure of assumptions made in the research
Projections using mathematical modelling involve assumptions and estimates made by researchers. Previous reports published by the HKU team clearly stated the assumptions and estimates made, that is, the basis on which their predictions were made. For example, one of the assumptions influencing the predicted outcome was the estimated effectiveness of tightened social restrictions announced by the government.
Different assumptions made by researchers will generate very different projections. It is important that any claims made by health experts – like the one related to the sixth wave – should be accompanied by a disclosure of assumptions made in the research. The lack of such transparency will only preclude informed discussion of new findings.
Predictions can go wrong, especially when they involve changing human responses and environmental factors, coupled with a new, evolving virus. In the United Kingdom, several models by leading scientists have been criticised for overestimating the number of daily infections and deaths at different phases of the pandemic.
No one can accurately predict the future. Even the best minds need to go through trial and error before developing better knowledge of the world. Next time, when Hong Kong experts are about to announce their new predictions, it would be useful to hear from them the things they got right and/or wrong in previous projections, and why.
Dr Yvette To, postdoc, department of Asian and international studies, City University of Hong Kong
