Introduction Logistic regression is often used to analyze experiments with binary outcomes (e.g., pass vs fail) and binary predictors (e.g., treatment vs control). Although appropriate, there are other possible models that can be run that may provide easier to interpret results.
In addition, some of these models may be quicker to run. Some may say that this point is moot given the availability of computing power today but if you’ve ever tried to run a hierarchical generalized linear model with a logit link function and a binary outcome, you know that when using R (using glmer or nlme) this may take quite a long time (and cross your fingers that you don’t have convergence issues).
In our module on regression diagnostics, I mentioned 1) that at times (with clustered data) standard errors may be misestimated and may be too low, resulting in a greater chance of making a Type I error (i.e., claiming statistically significant results when they should not be). In our ANCOVA session, I also indicated that 2) covariates are helpful because they help to lower the (standard) error in the model and increase power.