The insidious cost of increased class sizes: A TA’s perspective

UC Santa Cruz, like all UC schools, is in the midst of a massive regent-mandated effort to increase enrollment. In the face of a governor hostile to the idea of investing in education (despite his prior promises), the regents have decided that we are going to grow our way out of the budget shortfall. Much has been said about the foolishness of this plan from the standpoint of housing, student tuition and access to resources, but I thought I’d talk about the cost it has had on me personally as a Teaching Assistant (TA).

TAs are usually graduate students working on a doctorate or master’s degree. We are paid 50% wages on the assumption we spend 20 hours a week working on TA stuff to support our other 20 hours (ha!) of work a week on our thesis and classes. Our tuition is waived and we receive health benefits.

In the last two years, my department’s academic division has been cutting TAships while pressuring the department to enroll more students. For four years, I’ve been teaching the lab section for Environmental Geology (EART 20), which has given me a natural laboratory to note the impact that increased class size has had on my instruction. I’d also note that my experience has been less extreme than other TA’s because EART 20’s enrollment has been flat overall during the time I’ve taught. But the lab section has doubled in size from 22 to 45 students, possibly because we have more majors declaring and they need the lab credit for their degree.

Here are some ways my instruction has been impacted by doubling of students:

Grading time

As a TA, I am supposed to only spend 20 hours a week on instruction. I’m literally not allowed by my union to spend more time than that. And fortunately, because I have been able to slowly tweak my lesson plans over many years, I now have a lot less prep time than I did when I started teaching this class. The lesson plans are already put together, and I can just focus on polishing and perfecting the lessons. However, the time I need to grade has ballooned to at least double what it used to be. I say at least double, because I usually get tired after the 30th lab and start to slow down.

My detail in grading is also impacted because I cannot spend as much time looking and commenting on each student’s assignment. So while they’re paying higher tuition than their compatriots from four years ago, they are getting less instructor time dedicated to feedback on their work. Note that our department has tried to make up for this by hiring graders to assist TAs, but I insist on grading my own labs because I need to understand how students are learning and responding to my assigned material.

Less physical space for students

Our building used to have large, luxurious desks perfect for specimen-rich lab sections. But they unfortunately couldn’t fit more than 20 students in a room with those so they have put in smaller, flimsy desks to stuff more students in. These desks are narrow and crammed together to allow up to 30 students in the room. As a lab instructor, I prefer to walk around and answer student questions looking at the specimen we’re talking about until they understand and have that light-bulb moment. But I can’t do that anymore because the desks are so close together. So instead I now sit at the front of the room and they come up to me. I hate this and I know I get less questions than I would if I could walk around. It is another way that they aren’t getting their money’s worth.

Less interactivity

The UC claims to be a big cheerleader for the active learning style of teaching. Active learning is different than the classic lecture-based format in that exercises are designed to maximize student participation and interactivity between the student and instructor, hopefully leading to learning by experience rather than example. But active learning requires more grading time and a different classroom layout than the classic lecture format. And I have had to revise my labs over the years to reduce interactivity out of necessity. In the past, I’ve made a landscape out of play-dough for students to map out topographic profiles. This year, there were just too many students for it to work. They scrunched together around the model, with some deciding to wait until my office hours to get time doing it. It was sad to watch this. Next time, I’ll make two models to space through the room so it isn’t so claustrophobic.


These problems are only going to get worse, as our department is currently under pressure to increase enrollment and has less TAships to offer every year. We are often criticized for our low student to instructor ratio! Yet tuition is increasing. Students are getting less value for the same course offered four years ago. I’ve observed it with my own eyes. I feel a pang of sadness each lab section seeing the ways it reduces the quality of instruction. I spend more time to try to lessen the impact of these creeping changes, but something’s got to give. I hope Californians realize that the value of our legendary UC schools is under attack. I hope we invest more into education and don’t forget that the UCs helped make our state great. I hope Jerry Brown cements his legacy by increasing UC funding.


Behold, my new favorite creature
Porcellanopagurus nihonkaiensis wearing a bivalve shell (Source)

Some of you may be aware that I harbor great affection for hermit crabs. I own terrestrial Caribbean hermits. Your mental image of hermits may feature a wardrobe of gastropod (snail) shells, which are by far the most common mollusk contractor they use to construct their homes, but as I’ve discussed, they actually have great flexibility in their choice of abode. It turns out that there is yet another option which hermits take advantage of as a mobile home: the flat shells of bivalves and limpets!

What a cutie, wearing a limpet like a hat (source)

Porcellanopagurus nihonkaiensis is a species of marine hermit found off the coast of Japan. It uses the relatively flat, unenclosed shells of clams (and also limpets) for protection. Though lacking the 360 degree protection afforded by a snail shell, bivalve shell valves can be more plentiful in the marine environment, and being able to utilize a different shell frees them from competition with other hermit species which are specialized to work with snail shells.

Without the shell! From Yoshikawa et al, 2018

Hermits typically have a long, soft coiled body which fits in where the snail’s body once was, using “uropodal endopods” (little feet at the end of their bodies) to hold themselves in the shell. Some species like Porcellanopagurus, however hold a bivalve or limpet shell on their backs, which still provides protective cover for their bodies. One recent study talked about their method of acquiring and holding the shell. They actually took a cute little series of pictures showing how the crab picks up a shell it with its front claws, places it on its back and then holds it in place with their fourth pair of legs. So now I’ve found a creature that combines my beloved clams and hermit crabs in one fun package. Gonna have to keep an eye out if I ever dive off of Japan!

Play by play of how they pick up and carry away their new home (in this case a limpet shell) (source)