Khan AcademySick of Impact FactorsI am sick of impact factors and so is science. The impact factor might have started out as a good idea, but its time has come and gone. Conceived by Eugene Garfield in the 1970s as a useful tool for research libraries to judge the relative merits of journals when allocating their subscription budgets, the impact factor is calculated annually as the mean number of citations to articles published in any given journal in the two preceding years. But the real problem started when impact factors began to be applied to papers and to people, a development that Garfield never anticipated. Twenty years on from Seglen’s analysis a new paper by Jerome Vanclay from Southern Cross University in Australia has reiterated the statistical ineptitude of using arithmetic means to rank journals and highlighted other problems with the impact factor calculation. Vanclay’s paper is a worthy addition to the critical literature on the impact factor. The trick will be to crowd-source the task.
Today’s key fact: you are probably wrong about almost everything | NewsBritons overstate the proportion of Muslims in their country by a factor of four, according to a new survey by Ipsos Mori that reveals public understanding of the numbers behind the daily news in 14 countries. People from the UK also think immigrants make up twice the proportion of the population as is really the case – and that many more people are unemployed than actually are. Such misconceptions are typical around the world, but they can have a significant impact as politicians aim to focus on voter perceptions, not on the actual data. Bobby Duffy, managing director of the Ipsos Mori social research institute, said: These misperceptions present clear issues for informed public debate and policymaking. The actual percentage of Muslims in the UK is 5%, but those surveyed by Ipsos Mori said they thought it was 21%. Britons meanwhile underestimate the proportion of Christians, believing it is 39% when the correct figure is 59%. But each country has its blind spots. As Duffy puts it: