President Bok said yesterday he favors exploring alternatives to prohibiting one-semester, spring-term leaves of absence as a way of relieving overcrowding in the House during fall term.

Bok said at a news conference yesterday that leaves of absence are "legitimate and often of educational value," and said "there is a real cost involved in placing an inhibition" on them.

He suggested two possible alternatives: a limited restriction on leaves, rather than a full prohibition; or an arrangement that would allow a small number of additional students to study at Harvard during spring term only.

The plan to eliminate one-semester spring leaves was presented informally to the Administrative Board by Dean Whitlock late last month.

The housing problem stems from an imbalance between the number of students enrolled for the spring and fall terms, Bok said. This results either in overcrowding during the fall or a lower-than-normal number of students during the spring. The latter condition may tend to increase rooming costs, Bok said, because the costs of maintaining the Houses remain the same.

Bok said that if the University decides to limit spring leaves, students opting to take time off would not be guaranteed a room in a House if they return in the following fall, depending on enrollment.

Bok also suggested the study of a plan similar to one used at Princeton, which admits 30 to 40 students for its spring term with the understanding that their admission is for that term only.

This gives outside students the opportunity to study an area of special interest or under a particular professor, Bok said, and "might offset the imbalance and make it unnecessary to inhibit spring leaves."

Bok said he was unaware of any disadvantages of this plan, and added that "this kind of alternative should be thoughtfully considered."

More than 190 students took one-semester spring leaves last year. When Whitlock presented his plan last month, he said an increase of leaves this year could aggravate the expected housing crisis this fall.

Bok said he was neither for nor against the plan, but would like a "more sophisticated discussion from University Hall."

Whitlock could not be reached for comment yesterday.