When most of Yale’s campus was asleep at 9 a.m. on Sunday morning, more than 100 high school students flooded Kroon Hall to learn about brain tumors, mathematical symmetry and robotics.

The third annual Yale Engineering and Science Weekend (YES-W) — a three-day program run by the Office of Undergraduate Admissions — drew over 100 highly qualified science and engineering high school seniors from the class of 2017 applicant pool to visit campus and participate in science-related events from Feb. 16 to 18. Though the Admissions Office reached its goal of building an incoming class with 40 percent of students planning to major in the STEM fields for the first time last year, it continues to seek the same percentage of science-oriented students for its next class.

The program, which is part of the Admissions Office’s larger plan to recruit the country’s best science and engineering students to Yale, followed a similar format to last year’s weekend and introduced the prospective students to faculty, current students and research opportunities. Jeremiah Quinlan, deputy dean of admissions, said organizers relied on “the success of previous weekends” to design this year’s YES-W.

“We still take immense pride in the quality of our on-campus programming, and it takes a lot of time and effort to bring all of Yale’s resources together in such a showcase,” Quinlan said, adding that dozens of admissions officers worked with a team of students to organize the weekend.

The schedule for YES-W this year included several master classes with faculty, an undergraduate research symposium and a panel of young alumni, in addition to campus tours and meals in the residential colleges. On Saturday evening, students competed to build a Rube Goldberg machine in the Center for Engineering, Innovation and Design.

High school students at YES-W — all of whom received “likely letters” indicating their probable admission to Yale — said they enjoyed the weekend’s events, though most said they are still undecided about where to attend college. All 11 students interviewed said attending YES-W sharpened their knowledge of Yale’s resources and offerings.

“They are definitely spending a lot of energy trying to get us to come to Yale, and I think it’s working,” said Daniel Chen, a YES-W attendee. “Talking to current Yale students, their interesting points of view made my opinion [of Yale] better than it was before.”

Another student, Claire Mellon, said she “never really thought of Yale as an engineering powerhouse” before coming to campus. She added that receiving a likely letter and being invited to the program made her consider Yale more seriously.

Vince Wilczynski, deputy dean of the School of Engineering and Applied Science and the leader of a Saturday master class on engineering and design, said he enjoyed speaking with excited high school students and witnessing the impact of that excitement on current Yale students involved in YES-W. He added that he feels the weekend gave students a view of Yale’s science offerings beyond the current admissions materials.

“There are things so new that they’re not yet in the Admissions Office’s promotional materials, like the CEID and the engineering café,” Wilczynski said. “And you can’t document the connection between faculty and students …  except in person.”

Yale students who previously participated in YES-W during their senior year of high school also said the weekend significantly changed their level of commitment to Yale.

Bechir-Auguste Pierre ’15, who attended the pilot year of the program in 2011, said YES-W provided a strong introduction to Yale’s science culture.

“I was really shown that professors care,” he said. “[I also saw] the kinds of research undergraduates were doing — not just cleaning laboratory tools, but actual research.”

This year’s YES-W will officially conclude with a reception in Luce Hall on Monday at 5 p.m.