Since time immemorial, dance has been the least "respectable" of the arts -- what can you expect of an activity that depends so greatly on the flaunting of the body, in all its raw, sensuous presence? For this reason, among others, it's been an uphill struggle for dance to establish its credentials within institutions of higher learning.

Nevertheless, since the first quarter of this century American colleges and universities have figured importantly in the nurturing of dance, and particularly the branch known as modern dance. The three performance programs of this year's National College Dance Festival, this past Thursday through Saturday evenings at the University of the District of Columbia, bore witness to the accelerated progress of recent years. Apparently the "dance boom" of the '70s is still having a surging ripple effect on the nation's campuses.

The festival's sponsoring organization, the American Dance Festival Association, was founded in 1973 and began by presenting modestly scaled "regional" events. The first two festivals of national scope -- in 1981 and 1983 -- took place in Washington, at the Kennedy Center.

The just-concluded 1986 festival was by far the most ambitious in size and scope -- a mammoth task for its organizers. By now there are 165 participating institutions, and a correspondingly enlarged framework of workshops, classes and performances. Inevitably, the event reflected some of the down sides of academia and committee planning -- too many speeches, overloaded programs and rather convoluted organization.

The academic setting also still appears to favor generally conservative esthetics. The offerings of this year's festival, as those of the past, showed little trace of the contemporary trends of professional dance, though it's hard to know whether this mirrors student leanings or the predilections of festival directors. The most current fashions manifest in the programs were aerobic-gymnastic motifs and the use of original music based on tape collage or electronic synthesizers. The influence of ethnic idioms, social dance or postmodern ideas, for instance, was scanty at most.

On the other hand, the festival left no doubt that collegiate levels of choreographic and performance skills have been rising significantly.

It's impossible to indicate here, beyond a few highlights, the range and merit of the three evening programs, which included 31 works. The rationale for Thursday's program -- dubbed the "National Honors Benefit Concert" -- was obscure. Fewer than half of the nine pieces were performed by college dancers, and only two of the choreographers were students. It was wonderful to see such seasoned professional artists as Carolyn Adams and Danny Grossman in action (in an archly whimsical duet), but the college connection seemed elusive, as it did with other program entries.

Mark Dendy, who now directs his own company and was represented by "Wave," a precocious, sexually kinky quartet, was a choreographic award winner at the 1983 festival while he was still a student, so his inclusion made sense. Perhaps the evening's most impressive item was Arnie Zane's complex, high-voltage "Freedom of Information: Part III," as much for the intensity and precision of the performance by dancers from George Mason University as for the choreography by this prominent postmodernist.

All the performers on Friday night's program, labeled "Showcase Concert," and Saturday's, called "National Festival Gala Concert," were students, but the choreographers were a mixture of students, faculty members and professionals. The distinction between the evenings was that Friday's program was "invitational," where Saturday's was chosen by "adjudication." On both evenings, the dancers sometimes transcended their choreographic material, as with J. Christopher Potts in his own gargoylish "Smeagol's Demesne," and Karen Johnson in Tryntje Shapli's imagist "Scrimshaw II (The Lighthouse)." The quintet from the University of Wisconsin, Stevens Point, in Linda Caldwell's droll spoof of machismo, "Fantasy for a Few Good Men," not only danced splendidly but underscored the astonishing strength and number of male performers in this year's festival.

Student choreographers on both programs who showed uncommon imagination included Jose Luis Bustamente, in his mysterious "Roks" to music by Keith Jarrett, and Deborah Elliston, in her animalian sextet "Bidaka." Interestingly, none of the student work was as blatantly derivative as the pieces by professionals Lloyd Whitmore and Bill Evans.

To my mind, the gems of the festival were a pair of student works demonstrating creative spark of a high order. One was "Lullabyes," a pungently feminist minidrama about childbearing by Ana Sanchez-Colberg of Temple University (who also composed the wonderfully inventive score), trenchantly danced by her and Karl Schappell Saturday night. The other, Friday evening, was a bizarre nocturnal solo at the climax of which Laurie Goux, the choreographer and superb executant from Columbia College in Chicago, dribbled ice cubes onto the floor along a receding diagonal from a small black bag held at her chest. "Saturn Over Sunset" was the title of this spare, primal ritual, much abetted in its impact by the exotic tone clusters of John Cage's "Sonata No. 10 for Prepared Piano."