I spent half of my undergraduate career figuring out what I didn’t want to do. I started off in the journalism program, switched to literature, was undecided for a few panicked, free-floating months, and studied photography for a time. But the spring of my sophomore year, I enrolled in a fiction-writing workshop with an instructor named Harvey Grossinger.

Harvey was a tall, broad man with a trim gray beard. He was gruff but kind to his students, without coddling them. He insisted that we sit at a round table. My stories would come back to me with his notes crammed between lines and creeping up the margins. His comments on my prose and on the psychology of characters—his particular specialties—were unfailingly astute. One story of mine ended with the protagonist speaking about a fuzzy photograph of a girl he’d known. “Her face is a blur,” I’d written, “and he doesn’t know why.” “Yes,” Harvey scrawled beneath. “He does. And you do, too.” I did. Stapled to the top of every returned draft was a piece of colored stationery—teal, gold, red—filled from beginning to end with single-spaced narrative comments. He signed every letter “HLG.”

These critiques treated my stories as serious things, as pieces of art worthy of real criticism. I took the class once, twice, a third time as an independent study. Eventually, I couldn’t fit it into my schedule anymore. I graduated—just in time for the recession—and moved to California.

What I didn’t know at the time—and what I wouldn’t figure out for the better part of the next decade—was that Harvey was an adjunct. He didn’t tell us, and I didn’t know to ask. As an undergraduate, I never heard the term.

Adjuncts are generally hired on semester-to-semester contracts, given no health insurance or retirement benefits, no office, no professional development, and few university resources. Compensation per course—including not just classroom hours but grading, reading, responding to student e-mails, and office hours—varies, but the median pay, according to a recent report, is twenty-seven hundred dollars. Many adjuncts teach at multiple universities, commuting between two or three schools in order to make ends meet, and are often unable to pursue their own academic or artistic work because of their schedules. In the past four decades, tenured and tenure-track positions have plummeted and adjunct instructor jobs have soared, second only in growth to administrators. Adjuncts have always had roles to play: filling in for a last-minute class, covering for a professor on sabbatical, providing outside expertise for a one-off, specialized course. But the position was not designed to provide nearly half of a school’s faculty or the majority of a person’s income. It’s estimated that adjuncts constitute more than forty per cent of all instructors at American colleges and universities.

The first National Adjunct Walkout Day was held late last month, reportedly prompted by a proposal from an anonymous adjunct instructor at San Jose State. Some teachers went on one-day strikes; others talked to their classes about what the walkout was meant to demonstrate. Around the same time, the magazine Pacific Standard published an essay called “Are Adjunct Professors the New Fast-Food Workers?” It generated so many responses that they have just followed it up with a special issue devoted to the topic. The uptick in adjunct advocacy can be traced in part to the 2013 death of Margaret Mary Vojtko, who taught for twenty-five years at Duquesne; Vojtko’s full story is a complicated one, but her death highlighted how little universities are providing for the kind of teachers they increasingly depend on.

Harvey’s collection of stories, “The Quarry,” won the Flannery O’Connor Award for Short Fiction in 1997, among other prizes. He had an M.F.A. from my alma mater, and taught there as a teaching assistant for a few years before receiving a full-time position. That position had a five-year term, and after that ended he became an adjunct, splitting his time between two local schools—advising thesis students and teaching classes—until that work dried up, too. By his count, he has sent more than thirty students to graduate schools, including Julia Fierro, whose first novel, “Cutting Teeth,” came out last year, and Josh Rolnick, whose debut short-story collection, “Pulp and Paper,” won the John Simmons Short Fiction Award in 2011.

In California, I found a job that I hated but that I thought would be temporary. Two years later, I was still there and miserable. I hated the Bay Area and its mercurial, damp weather and sky-high rent and new-age judgment that clung to everything. My boyfriend and I broke up. I read and wrote and watched a lot of “Buffy the Vampire Slayer.” And I decided to apply to M.F.A. programs. A lot of them, all over the country, anything to get me out of California.

I e-mailed Harvey for advice. He’d mentioned M.F.A. programs a few times in passing, and I thought that he might be able to write me a letter of recommendation.

But he did more than write letters. He asked me to send him what I was working on, and returned stories I’d e-mailed him by post—in thick, heavy envelopes—annotated the same way they’d been in school. When I got closer to deadlines, I sent him draft after draft, half a dozen in a week. He encouraged me to apply to as many funded programs as I could, and wrote letters for all of them. When I thanked him, he’d just tell me to keep going.

After I got the acceptance call I’d been waiting for, the one I’d dreamed about, Harvey was the first person I called.

“I got in,” I said, my voice cracking.

“Of course you did,” he said.

“I can’t believe it.”

“I can,” he responded, then chuckled. “I’m kvelling right now.”

“What does that mean?” I asked.

“It’s like you’re my child,” he said, “and you’re onstage and dancing beautifully, and I’m so, so proud.”

When I got to graduate school and began investigating post-graduate work, I finally learned what it meant to be an adjunct, and what such positions entailed. When it occurred to me that this was the job Harvey had, I was embarrassed by my naïveté, and angry that the school had never spelled this out for me, had never made it clear that so much of the work that Harvey did for his students was essentially uncompensated.

We like to rhapsodize about the influential teacher who changes lives and hearts, and makes students stand on their desks in academic ecstasy. But this doesn’t translate in the contemporary world of higher education. There is a complicated culture of silence that surrounds adjuncting. Schools have no incentive to draw attention to how many adjuncts most institutions now rely on, and as for the adjuncts themselves, addressing the subject raises awkward questions, and might even put their jobs at risk: in her essay “The Teaching Class,” Rachel Riederer recounts how merely explaining how adjuncting worked to a group of students outside of class threw one adjunct’s job into jeopardy. There also can be an element of shame, or reservations about discussing financial matters, or a reluctance to complain. Harvey tells me he didn’t think of it as a secret; it just never occurred to him to bring it up. “I would’ve told anyone who’d asked,” he said.