'I can't come to class now, my favorite soap is on'

For most of the time Scott Simmons was a student at Dartmouth College in Hanover, N.H., 3 p.m. was a special time. Three or four days a week at this hour he was in the ''tube room,'' as the television room was called in his fraternity , settled down on one of several old couches, and watching his favorite ''soap, '' ''Guiding Light.''

''I arranged one or two classes around that,'' recalls Mr. Simmons, who graduated last June.

When he was younger, he says, ''I always laughed at my mother and father for watching their ridiculous soaps.'' Today he says: ''It's funny, but you get caught up in it.''

As a student soap fan, he is far from alone.

Recent research, some of it still under way, is uncovering a previously suspected but little-documented audience of soap fans among college students and even preteen-agers.

Some 56 percent of the college students surveyed at about a dozen universities last year said they sit down to watch a soap at least once a week.

Many of them, like Simmons, are quite ''loyal'' to particular programs, the research shows. Some programs '' have almost a cult following,'' says Barry Sherman, a professor of telecommunications at the University of Georgia School of Journalism, who participated in the survey.

And soap watching is big among preteens, too, according to a study not yet completed by a teacher at the University of Rochester. Elaine Yudashkin has interviewed 200 children ages 10 to 12, who watch soaps at least three times a week, to see what effects it has on them.

''Many watch five days a week, '' she says. ''They love them. They are absolutely loyal; they would not miss them. They remember plot lines.''

Some of the children began watching soaps at age 7 or 8, she adds.

Findings about the college soap fans are being distributed to advertisers by ABC, which paid for the study. While these soap fans may not buy detergents, they are buyers of stereos, 35mm. cameras, and alcoholic beverages, according to questionnaires the students responded to during the surveys.

The research can be used in attracting new sponsors, says Guy Lometti, supervisor of social research for ABC.

But a more precise figure for advertisers may be the finding by A. C. Nielsen in 1980 at the University of Wisconsin in Madison. Some 8 percent of the students in dormitories, fraternities, or sororities were watching afternoon soaps at any one time, says Travis Whitlow, promotion manager for Nielsen. But the total number who watch is larger, he says, because it's not always the same 8 percent.

This 8 percent and the ABC finding of 56 percent during the week are not necessarily contradictory, Mr. Whitlow says. They just measure college soap viewers in different ways, he says.

Nationally, among all viewers, some 6.11 million people over the age of 2 watch at least 15 minutes of soap on any afternoon, Whitlow says.

Are the soaps useful to college students? Or just a waste of time?

''College students use soaps, I believe, to understand the older generation, '' speculates Mary Cassata, professor of mass communications at the State University of New York at Buffalo and co-author of a new book on soaps.

Soaps are not, however, an accurate reflection of American life, but an ''exaggeration. . . . Everything is dramatic,'' she says. The most common characters, she says, are ''wealthy . . . well educated, liberal minded.'' Some of the soaps are becoming more youth-oriented. And use of alcohol is quite frequent on soaps, she adds.

Soap watching among college students is often a social event. The ABC study showed nearly 70 percent of the students watched with one or more people.

There are also a number of adult soap (and other television) audiences not counted by national surveys, says Nielsen's Whitlow, in prisons, motels and hotels, senior-citizen homes, and hospitals. At Buffalo General Hospital, for example, the lounge is jammed at 3 p.m. to watch General Hospital, Professor Cassata says.

And, in Washington, a now-graduated Scott Simmons occasionally still takes a glance at his favorite soap between assignments on his job in the office of a congressman.