I am quite new to R and is setting up a mixed effect model. I have a large dataset and want to include 3 random effects that are nested. I have data from 2 years, 2021 and 2022, and there are rounds of experiments every year, that are named experiment 1, 2 and 3 and so on on each year.
The problem is that for the random effects, the number of experiment rounds are calculated wrong, as the numbering of the experiments are the same for each year. How can I include “year” for the random effects so the number of groups will be correct?