Randomization

The primary goal of randomization is to distribute potential confounding variables evenly among treatment groups and therefore to minimize the selection bias and enhance internal validity of the study.

In general, we distinguish between two basic types of randomization:

• Simple randomization: Participants are randomly assigned to different different groups

• Stratified randomization: Participants are grouped based on certain characteristics (strata)

Hubro implements simple block randomization without stratification as a default method for randomizing participants in the study.