I am kind of curious about this as a first-time applicant. There is so much emphasis on the research aspect of programs that I just realized how fuzzy the idea of doing a practicum is. What is a practicum like? How many patients get seen per week? What is supervision like?
It is going to vary a lot depending on where you go and what kind of practicum it is.
For example, in a neuropsych testing practicum, I remember seeing a patient for a full day evaluation every two weeks (early on). The other day of the week was for scoring, didactics, individual/group supervision, case conferences, grand rounds, etc, and it was expected that you would reading a lot of literature and doing some writing on your own to round out 20 hours per week. You had the "off" day the following week to focus on the report. Once you got more efficient with assessments/scoring/writing, sometimes you would do a full evaluation every week (thus you'd get a total of at least 25 and maybe up to 35 full neuropsych batteries done each year).
Therapy practica will also vary. If you are in a setting with a lot of no shows (e.g., CMHC), you might schedule more patients than you need and do a fair amount of case management. I've seen some combined practicums where you carry 4-5 therapy patients, do a group or two, and also do intakes and testing cases (then of course didactics/supervision). I've seen practica through health systems where you generally carry 8-10 therapy cases and spend the rest of the time charting and in didactics/supervision.
I know that there are other models out there as well, but all of the ones I am familiar with have involved 20 hour weeks for 12 months (typically July 1 to June 30). How the time is split up has varied (e.g., two 10 hour days, a few days a week for shorter duration, 2 days + Friday 1/2 day of didactics, etc).
One thing I heard recently was that some practicum sites don't do didactics. My program would never have allowed us to go to one of those sites, but I suppose it is one way to cut down on your weekly time commitment (but probably reflects a poor training environment, and if you are just at the practicum level, don't you actually want training?!).