How to consider multiple rows for a given Participant ID
This is a pretty elementary question, but how should one go about analysis of a large human clinical research data set with multiple rows for a given participant? Lets say there are columns titled "ParticipantID", "Visit", and "HasBeard" each containing categorical data. For each ParticipantID (i.e. 001; 002; 003) there are multiple study Visits (i.e. V1; V2; V3 etc) with each Visit containing uni...