The UK government used a statistical algorithm to alter children’s grades for exams missed in lockdown. But critics have argued that this algorithm, which used old data on school performance, unfairly stigmatised pupils from poorer backgrounds. Stian Westlake from Britain’s Royal Statistical Society speaks to Gareth and Bill about the challenges of creating such an algorithm and where the government went wrong.The Language of Trolls What is it like to work as a Twitter troll? Researcher Sergei Monakhov, from the Friedrich Schiller University in Germany, used this question to discover how the language used by trolls is different from that used by regular users. He discusses how these patterns can be used to spot troll’s social media posts much more quickly.Saving lives with data in Africa A digital tool-kit has been designed to help governments and health organisations in Africa tackle the spread of Covid-19. Dr. Sema Sgaier, executive director of the Surgo Foundation describes the Africa Covid-19 Community Vulnerability Index, which maps regional data on health, economic, and social robustness to find where Covid might hit hardest.(Photo: Student protesters hold up banners. Credit: Andrew Milligan/PA) Producer: Julian Siddle