The group “Pre-med? Not Anymore” boasts a menacing image of four people clad in scrubs with a blood-red slash over their grinning faces.

Although the group only has 15 members at Yale, other students said some of the University’s introductory science courses convinced them to shift their studies from molecules to Milton. Still, some professors said the curriculum does not discourage students with a genuine interest in scientific fields.

Statistics from Yale’s admissions office and the Office of the Registrar indicate that such shifts are not uncommon. Dean of Undergraduate Admissions Jeff Brenzel said of the 1,321 members of the Class of 2009, approximately 29 percent indicated they intended to major in engineering, the life sciences, mathematics or the physical sciences. The registrar reported that of the 1,401 students who graduated this past year, only 19 percent majored in the sciences.

“On the data regarding intended major, many students change their minds between the time they apply and the time they graduate,” Brenzel said.

Students said their reasons for straying from the sciences range from personal issues to what they see as inadequacies in the departments.

Peter Nicewicz ’08, a member of the facebook group, said he took several science and math courses as a freshman in preparation for applying to medical school. Now, he is an English major and no longer considers himself pre-med. He said he left the sciences because he did not think his professors connected their subjects to his primary interest — the medical field.

Upon entering Yale as a freshman, Jane Gallaudet ’07 planned to major in cognitive science and then attend medical school. Like Nicewicz, Gallaudet took several science courses her first semester. She said her dissatisfaction with these courses compelled her to re-evaluate her interests.

“It burned me out,” she said. “It was stressful, and I didn’t want to do it anymore.” Gallaudet said.

Gallaudet said that her experience in Chemistry 114, the class taken by many pre-med students to fulfill the general-chemistry requirement for medical school, contributed to her decision to switch to a major in philosophy.

“I feel like [the professor] writes the tests so people don’t do well on them,” Gallaudet said. “It was really disheartening.”

Students’ previous knowledge of chemistry varied widely, Gallaudet said — though some had already taken Advanced Placement Chemistry in high school, she and others felt underprepared.

Nicewicz also said he felt a negative attitude from science professors toward pre-med students in their introductory classes.

But Douglas Kankel, the director of undergraduate studies for the Department of Molecular, Cellular and Developmental Biology, said he is not convinced that introductory courses deter students from majoring in the sciences or from applying to medical school.

“The population of students that come to Yale are exceptionally qualified,” Kankel said. “I’m not sure that people who are really interested in medical school have any difficulties.”

Cassandra Rodriguez ’08 fulfilled all her pre-med requirements at a university near her home in Texas, but she is now unsure if she wants to attend medical school. As a history major, she said she feels restricted by the sciences as a subject.

“The subject matter never changes,” Rodriguez said. “It’s not as interesting as history, where there are different topics coming at you all the time. There’s not a lot of room for your own ideas to take form.”

Nicewicz said he thinks science professors are too focused on their subjects to make them relevant for students interested in medicine. He said this caused students to feel distant from their professors.

The inaccessibility of science professors is a common complaint, Gallaudet said. “A lot of people say that you don’t want to waste your time in classes that are badly taught,” she said. “It seems like a waste of time to be in a class of 200 with teachers who don’t care.”

Leo Buss, director of undergraduate studies for the Department of Ecology and Evolutionary Biology, said that although students have told him that their experiences in introductory biology courses contributed to their decision to explore subjects outside the sciences, the courses are not meant to be a mechanism for weeding out students.

“I taught introductory biology for 15 years, and that certainly was never my intent,” Buss said.

Buss said students’ shock after receiving a poor grade is not unique to the sciences at Yale. He said many students are equally distressed by their first bad grade on an English paper.

“It is certainly the case that people set high standards,” Buss said. “Inevitably, there are some who fail to meet them.”

But Buss said he is concerned that science students are altering their career plans based on negative experiences in only one or two classes.

“Don’t give up,” Buss said. “It’s a very limited view of the field as a whole.”

Nicewicz said his friends’ decisions to venture outside the sciences were not based solely on their opinion of Yale science classes. Instead, he said, it was the result of a change in their interests and professional visions.

In spite of this, students and professors agree that some changes should be made to encourage more Yale students to explore the science curriculum.

Gallaudet said she is frustrated that Yale claims to focus on the sciences, while she sees some aspects of the program could be improved.

“The intro classes need to be with the best professors so kids aren’t turned away by some genius who can’t teach,” Gallaudet said.

Another way to make science classes more accessible would be to have smaller class sizes, Buss said.

“With large class sizes, it’s essentially impossible to detect and help people who are having trouble early on,” he said.

He said creating classes of 30 students, though an enticing prospect, would require a dramatic reorganization of the department. More professors would need to be hired, the number of upper-level courses would have to be reduced or professors would be required to teach more classes, Buss said.

But Rodriguez said it’s up to the students themselves to decide whether they can handle the science curriculum at Yale.

“It’s not an easy track to follow,” she said. “It’s not for everyone.”