Back when we first started the center in 1990 here at the University of Michigan-Flint, we were primarily walk-in. We had six rather large cubicles purpose built for the task. But being a four-year college, we found more and more students unable to meet with walk-in due to scheduling conflicts. Thus, we went to appointment based tutoring (we now use TutorTrac for booking and recording visits).
The upside is students make appointments when they need one as opposed to hoping our schedules coincide. The downside is that tutors are only paid when they get appointments, so there is no set of steady tutoring hours for them. We do have some lab tutoring for Nursing, math lab, and A&P, and we support about 40 sections of SI each Fall and Winter semester (less in Spring and Summer), but I'd say the bulk of our tutors' work comes via appointment based tutoring. It just seemed the most fiscally responsible way to go for our campus as we tutor about 100 courses across a variety of schools (the UM-Flint Writing Center is a separate entity not under our office).
Most of the tutors are fine with the appointment based system, and our biology, chem, physics and math people can get lots of work as there is a need out there. It is more spotty for tutors who support foreign language or social sciences, as work is not as frequently. That leads to issues with tutors using your tech systems infrequently and possibly forgetting how they work or to use them at all. Not a big issue now, but it had been in the past.
If you can get people to conform to your walk-in hours and deliver help to the students who need it, I think it's a great way to go. For our campus, however, we just seem to service more people with less waste by using the appointment system.
Michael B. Kassel, Ph. D.
Student Success Center
285 University Pavilion