Why most published findings are false: revisiting the Ioannidis argument

It has been more than a decade that Ioannidis published his paper entiled Why most published research findings are false. Forstmeier et al. (2016) recently revisited the Ioannidis argument, and I thought it worthwhile to prepare a blog post on the topic to cement my understanding. Looking for a novel effect Let’s consider 1000 hypotheses we might want to test.

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Calculating sample size using precision for planning

Most sample size calculations for independent or paired samples are performed based on power to detect an effect of a certain size, assuming there’s no effect. Instead, Cumming and Calin-Jageman recommend that readers plan studies to detect precise effects. The 95% confidence interval (CI) indicates precision about effects. Therefore, it is possible to plan studies to detect narrow 95% CIs

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R: How to reshape data from wide to long format, and back again

Many studies take repeated observations on subjects. For example, clinical trials record outcomes from subjects before and after treatments, and laboratory studies might record physiological outcomes from the same subjects over time. In a dataframe, when observations from each subject are written on one row and repeated observations are stored as different column variables, we say the data are in

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The likelihood ratio test: relevance and application

Suppose you conduct a study to compare an outcome between two independent groups of people, but you realised later that the groups were unexpectedly different at baseline. This difference might affect how you interpret the findings. For example, you measured muscle stiffness in people with stroke and in healthy people. At the end of the study, you realised that on

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