Students who found their shopping lists for this term clustered within the same time slots were not alone.

This fall, as in past years, seminars and large lecture classes are concentrated in the middle of the week during the late morning and afternoon, despite past efforts to get departments to assign course times more evenly. Administrators said the trend is driven by students and professors alike, who often prefer concentrating their class time in the middle of the week and avoiding early morning classes. Though administrators acknowledged that this leads to inefficient use of classroom space and limits students’ course options because of overlap, they said Yale College is unlikely to adopt stricter scheduling policies any time soon.

“It would require some further resolve on the part of the faculty to create [a firm policy to spread out classes],” Dean of Undergraduate Education Joseph Gordon said. “Although such guidelines would probably result in fewer ‘forced choices’ by students between course options, I don’t know that such a system would necessarily be welcomed by students, because that advantage would be bought at what some might perceive to be the cost of having to get to class earlier in the day and on more days of the week.”

Two-hour seminars are clustered in the afternoons, particularly between 1:30 p.m. and 5:20 p.m. on Tuesdays, Wednesday and Thursdays. By far the most popular time slot for these seminars is Tuesday at 1:30 p.m. — 64 seminars this fall meet at that time, compared to 44 in the next most popular time slot, Wednesday at 1:30 p.m.

Tuesdays and Thursdays are also more popular for 75-minute lectures to meet, with 51 lectures meeting at 1 p.m. on Tuesday/Thursday compared to only 25 at that time Monday/Wednesday.

Besides creating logistical problems, the trend raises questions about whether current scheduling patterns best fulfill Yale’s educational goals. Yale College Dean Mary Miller said students learn better when they do not cram all of their class time into a short period.

“I think pedagogically it is superior to have the acquisition of knowledge be less compartmentalized,” Miller said.

Several professors interviewed said shorter teaching weeks enable them to satisfy their other responsibilities as academics.

History professor Daniel Magaziner, who teaches only on Tuesdays and Thursdays this semester, said Yale has “rigorous productivity expectations” for its faculty that make it necessary for instructors to budget enough time for their own research and writing, as well as teaching. He said choosing a condensed class week generally helps with the issue.

Professors also said Mondays and Fridays can be undesirable teaching times if they anticipate traveling to conferences during the semester.

“I try not to schedule on Fridays because I wouldn’t want to cancel class,” psychology professor June Gruber said. “Tuesdays and Thursdays are safer in that way.”

In addition, professors said they are often responding to what they see as students’ preferences for classes in the afternoon and middle of the week. Magaziner said he has noticed “slight lags in attendance” on Mondays and Fridays when he has taught classes on those days. English professor and Francis writer-in-residence Anne Fadiman said Fridays seem to have been “annexed by most Yale students as an extension of the weekend.”

Deputy Provost for Academic Resources Lloyd Suttle said the University has encouraged departments to distribute their course offerings more evenly over the day and week “at various times in the past,” but these attempts “don’t always work” because they take the form of guidelines and not firm rules.

In 2007, the Course of Study Committee recommended that departments and programs spread out class meeting times so that no more than 10 percent of their classes of a given type, such as lectures or seminars, were offered during any one time slot, Assistant Dean of Academic Affairs George Levesque said. But even if departments follow this guideline, Assistant University Registrar Daria Vander Veer, who is in charge of class scheduling, said “sheer numbers still mean there is overcrowding on certain popular days and times.”

As popular class times shift to later in the day, they can also create added conflicts with athletic practices. Zachary Leonard ’89, head coach of the sailing team, said most of his athletes have to miss team practice — which starts at 2:30 p.m. Tuesday through Friday — at least once a week because of conflicts.

“When I was an undergrad [in the 1980s], we used to practice at 1:30 p.m., and only seminars would cause you to miss practice,” Leonard said. “Now, even trying to practice at 2:30 p.m., there are more classes students have to take for their majors that end later.”

But he added that it would be difficult for Yale to offer as diverse a range of classes as it does without holding classes in afternoon time slots.

Yale is not unique among Ivy League universities in having courses clustered in the middle of the week, but some schools such as Brown University are more successful in spreading out their class offerings. A 2009 reaccreditation report by the New England Association of Schools and Colleges said that Brown “may be the best among its peers in scheduling classes five full days a week.” This was due partly just to practical issues: Brown’s university registrar, Michael Pesta, told the Brown Daily Herald in 2009 that Brown did not have enough classrooms to have a more condensed school week.

Several students interviewed said they were satisfied with the current system, since they are able to distribute their classes according to their preferences. Taylor Nicolas ’15 said she “basically [has] four-day weekends” because her only class on Mondays and Fridays is French. She plans on replicating this schedule in the future, she said, even though her back-to-back class schedule midweek is “rough” as a result.

But Emily Bosisio ’16 said a condensed week can be exhausting because “there’s a lot more work to do in a shorter period of time.” She added that she may try to spread out her course schedule more next term.

There are only 38 lectures and seminars in Yale College that meet on Fridays.