Data Sheet 2_Fit one model, report one number: how to analyse a training or intervention study.csv

A typical analysis, such as an analysis of variance or a mixed model, is powerful, but that power is for taking a measurement apart, not for delivering the verdict. Such a model splits each measurement into separate terms: a benchmark, covariate adjustments, a time course, and a term that lets each protocol follow its own time course.

The statistical software prints a separate test for every one of these terms, and a common workflow reports those tests as the study’s result. However, the study was built to answer only a single question, usually whether one protocol improves the outcome more than another as training goes on. Our position follows directly: choose that one comparison in advance and test it directly, reading it off the fitted model without first requiring an overall, or omnibus, test to pass.