Hello everyone!

I want to conduct a paired t-test for one variable (number of inventions) only for the TG at time points 1 (T1) and time point two (T2).

I’ve divided into training group (TG), control group (CG) (and one goup of something in between which I will not take into account for my calculations) based on the number of sessions in which the students have participated:

group_control <- ug123$train_a == 0

group_train <- ug123$train_a >= 5

group_none <- ug123$train_a > 0 & ug123$train_a < 5

For the first t-test I want to compare the number of early inventions in T1 and T2 only fot the trainings group.

How can I compute a variable for this?

Does it make sense to put the group into brackets [group_train] like the following:

t.test(ug123$t1_inventions[group_train], ug123$ t2_inventions[group_train], paired = T) ?

I’m thankful for any recommendations!

Svenja (R beginner)