Final Sample Size: Number of Clusters (Unit of Randomization)
Treatment was randomly assigned at the individual level (161 students randomized) but 16 students trained in groups of two students, so for these students the instruction was clustered. Total number of clusters in this sense was 153.
Final Sample Size: Total Number of Observations
Final Sample Size (or Number of Clusters) by Treatment Arms
82 students in the treatment group and 79 students in the control group.