Participants (N=12) in a study were randomly assigned to one of two types of therapy - either talk therapy or drug therapy (n = 6 per condition). Mood scores were analyzed at two time points for all clients: 4 weeks and 12 weeks into the start of the therapy. Mood scores are presented in the table below, with higher scores indicating improved / more positive moods. Use the data to answer the questions in this set.

Is this within subject or between subject