Teaching assistants at Yale University voted Thursday to join UNITE HERE, becoming the latest group of graduate students at private universities to unionize since the National Labor Relations Board cleared the way last summer.

Yale organizers took an unusual approach of having individual departments hold separate elections to speed up recognition by the university and build support for unionizing. Eight of the nine departments that held elections, including English, history and math, voted in favor of forming a union, while graduate teachers in the physics department voted against. There are a few uncounted ballots in the East Asian languages and political science departments that must be resolved by the NLRB.

“After months of conversation, we finally got to vote to form a union and to look out for one another. Now it’s time for us to sit down at the negotiating table and bargain a contract that addresses the issues that matter to us,” said Camille Cole, a graduate teacher in history and the secretary-treasurer of Local 33 — UNITE HERE.

UNITE HERE had granted Yale graduate students a charter in March, but the teaching and research assistants had to wait on the labor board’s decision to win bargaining rights. The teaching assistants are seeking funding security, mental health care, affordable child care, equitable pay and parity for marginalized communities in academia.

The rights and role of graduate students have become contentious subjects as more universities rely on low-paid adjuncts and doctoral students, rather than full-time professors, to teach — a model that has been widely criticized as exploitative. Although adjuncts have made inroads in their fight for higher wages, graduate students have struggled, in part, because the work they do is often a component of their education.

The NLRB changed the course of that struggle in August by overturning a 2004 Brown University ruling in which the board said graduate students engaging in collective bargaining would undermine the nature and purpose of graduate education. Doctoral programs often require students to teach or conduct research before earning their degrees, and as a result, universities argue that they have an educational, not economic, relationship with those students.

Yale was among many private universities to come out against the labor board decision, arguing that recognizing students as employees would undermine the foundation of their education. Days after the ruling, the Ivy League school warned students that forming a union could alter their relationship with faculty and limit their power as the union becomes their collective voice.

“These election results demonstrate the extent of graduate student division on the question of unionization,” Yale’s Graduate School of Arts and Sciences Dean Lynn Cooley said in an email to The Washington Post. “Even with the micro-unit strategy that so many have criticized as being un-inclusive, the union lost one of its own hand-picked departments, and failed to clearly win two others, with opposition spread across the physical sciences, social sciences, and humanities.”

Cooley said the “slim margins of victory and very low vote counts in many departments” underscore the concerns that a small number of students could be in the position to make decisions for everyone. The university, she said, is closely examining the outcome and will respond more fully in the coming days.

Since the NLRB decision, graduate students at several private universities have filed petitions or won the right to unionize, including Loyola University Chicago, Duke University and Harvard University.

There are more than 30 collective bargaining units representing more than 65,000 graduate students across the country, according to the National Center for the Study of Collective Bargaining in Higher Education and the Professions at Hunter College. The vast majority of those groups are at public universities, which are governed by state laws and not the labor board.