I am having some difficulties in constructing my random factor in lme4. My experiment design is the following: I have 3 groups of several individuals each. In each group, some individuals were selected for receiving a treatment (experiment) and others were not (control). A measure X was collected several times for each individual.
I would like to know if there is a difference between the individuals who received a treatment and those that did not. But beforehand, I need to make sure that I am assessing my model correctly:
- The hierarchical model is the following: Treatment/groups/individuals
- In lme4 this would be: X~Treatment*times +(1+ Treatment|groups:individuals)
Am I right?
Thank you in advance for your help.