Ms. Snyder has taught history at the college for a decade, and several current and former students on campus said in interviews that they had largely positive views of her. She was one of the first students when the college opened in 1968, then earned bachelor’s and master’s degrees at Montclair State University, and taught middle school social studies for more than 30 years.

For Philip, who has spent most of his life being home-schooled or attending a small charter school, the teacher’s attitude was a surprise and a disappointment. “I’ve never experienced any kind of discrimination,” he said, “so for it to happen in a college classroom was quite shocking.”

Jim McClure, a board member of the National Stuttering Association and its spokesman, said Philip’s experience is unusual — because most stutterers avoid speaking in class.

“Teachers ignore them, or have to coax them to speak out,” Mr. McClure said. “The fact that this guy wants to participate is a really healthy sign.”

Kasey Errico, who taught most of Philip’s seventh- and eighth-grade classes at the Ridge and Valley Charter School in Blairstown, N.J., noted that there were always students who monopolized class time.

“I wonder what this professor has done with those students, the ones who didn’t stutter,” Ms. Errico said. “If she told them the same thing she told Philip, then I might understand.”

Two students in Ms. Snyder’s class, who spoke on the condition of anonymity to avoid alienating their teacher, said that Philip did take up more time than the other students, but not egregiously so, and that his contributions were solid. They said they did not know what happened between him and Ms. Snyder, but did notice the day he held his hand up for most of the class and never got called on.