Yale wants students to major in the sciences. At our 312-year-old university, known worldwide for excellence in the humanities and social sciences, University President Richard Levin made a conscious choice to expand the scope and strength of the sciences at Yale. Over the past 15 years, Yale has invested over a billion dollars in the sciences.

Yale students want to major in science. The class of 2016 was the first to meet Yale’s recruitment goal of 40 percent science-interested admits per class. Some of those students visited during the new Yale Engineering and Science Weekend. They arrived in New Haven considering a major in the sciences.

Yet these same students will likely leave with degrees in economics, political science or history. President-elect Peter Salovey must now turn toward retention.

Introductory classes are the Achilles’ heels of Yale’s science departments. Students complain that their large lectures are devoid of camaraderie or community, burdened by dull teaching and indecipherable grading.

Yale hires professors who will teach undergraduates — this philosophy separates us from countless other research institutions around the country. But a willingness to teach should not be conflated with an ability to teach. Introductory classes must be guided by professors with charisma, creativity, and a clear and lucid style — and these popular professors must in turn mentor their colleagues in pedagogy.

And science seminars are too rare. Introductory lectures must be supplemented by smaller courses, where freshmen and sophomore science majors can gain easy access to advisers who can guide them through the entirety of their academic careers.

Science students still search for credit where credit is due. Awarding students only a half-credit for their work in a rigorous laboratory class discredits the work of those students, and can even discourage them from enrolling in future science courses.

And when those students explain transcripts filled with half-credit laboratories that took more work than two full-credit classes, they may also be unable to explain how they received their grades. Without transparency in grading, especially important given the use of curves in the sciences, students will continue to be scared away before graduation.

Science Hill still symbolizes the disconnect students across the disciplines can feel from one another. Distributing classes, regardless of department, more evenly across campus will do much to cultivate academic integration in the Yale student body.

The second-class status of the sciences on Yale’s campus need not be an inevitability of our historic strengths. With each of these suggestions, Salovey will show that Yale’s science programs must focus on retention as much as innovation. He will build a foundation for future excellence from the bottom-up, creating a self-perpetuating cycle of scientific improvement.