IN ``Robinson Crusoe,'' English novelist Daniel Defoe's classic 18th-century work, the hero reflects upon the marriage he entered into after his island ordeal and return to middle-class life. It was ``not either to my Disadvantage or Dissatisfaction,'' Crusoe says, with all the enthusiasm of a man describing the cutlet he ate for lunch. Recently, a group of students sat around a seminar table discussing the point. The instructor was observing how Crusoe, for all his ingenuity, was typical of the merchant class arising in England at the time, a man ``without emotion or wonder,'' who reckoned value almost exclusively on a calculus of personal loss and gain. Did not his view of marriage, the instructor suggested, betray a bit of the spirit of the Wall Street dealmaker, who outfits his wife with 16 credit cards and then is annoyed when she wants a portion of his time as well?
The quiet in the room seemed to become palpably deeper. Among the class were several who had seen more winters than the usual graduate student. Had one of the women been in such a marriage? Or had they known someone who had?
It was an ``adult education'' class -- ``night school'' -- and it illustrated the way literature can come alive when students have had experience in the world. In the process, it suggested a happy consequence of the adult-education revival in the United States today.
People in the field reel off the statistics: Over the last decade, the number of people 25 and over enrolled in colleges and universities grew by over 70 percent. Part-timers now account for over 45 percent of all college students, and the College Board estimates that by 1990 these ``nontraditional'' students will be the majority.
Whether they are baby-boomers hitting their 30s, single mothers trying to climb the employment ladder, or steelworkers who need new skills, part-timers and adults are becoming ``the central reality'' of higher education today, says Noah Brown of the National University Continuing Education Association (NUCEA) in Washington.
Adult education has long been disparaged as a kind of K mart of higher education, associated with dingy classrooms in seedy downtown YMCAs. More recently, it has come to be seen as glorified vocational education or as a ``dating service'' for urban singles, as a professor at one of the better programs put it.
Generally, the academic community subscribes to these views. ``The faculty still loves to snicker,'' says Howard Hodgkinson, a senior fellow at the American Council on Education and a leading authority on how population changes affect schools. ``If you want to be president of the faculty senate, the worst way is from the base of continuing education.''
But quietly, the best of adult education has become something very different from the stereotype. Administrators, teachers, and students describe an enterprise where students come eager to learn, where teachers love to teach, and perhaps the most important innovations in American higher education are taking place. It will be seen as the ``cutting edge of the next few decades,'' says David Mitten, professor of classic art and archeology at Harvard University.
Adult education's lack of status may be the proverbial blessing in disguise. ``One of the most interesting places to be is on the margin,'' says Leonard Freedman, dean of the University of California at Los Angeles (UCLA) extension and a professor of political science.
In the view of Mr. Freedman and others, adult education is a kind of Off Off Broadway for higher education. Free of football scandals, faculty politics, and the publish-or-perish ethic, adult programs can experiment in ways that are extremely difficult in the academic mainstream today.
``No new idea in the credit area hasn't come from the nontraditional area,'' says Stanley Gabor, who heads the extension studies at Johns Hopkins University in Baltimore.
An emphasis on teaching -- long a sore point at large research universities -- is an example. ``We don't ask for research,'' Mr. Gabor says. ``We ask for teaching.'' While tenure can be important, it can put professors in the classroom who would rather be in the library, and limit courses to the specialties of these teachers.
``I don't deal with tenure,'' says Michael Shinagle, dean of Harvard's extension program (and instructor in the Crusoe class described above). ``I can say, `I don't want you,' '' even to the school's most renowned faculty members, he says.
Extension schools regularly seek student evaluation of teachers. UCLA is among those that ask for it in every course. The students ``paid their money,'' UCLA's Freedman explains. ``They gave up their valuable time. And, by golly, they want a good teacher.''
This emphasis on teaching helps to keep costs down. ``We only pay for what we get in terms of class instruction,'' rather than underwriting research as well, says Allan Hirschfield, executive vice-chancellor of University College at the University of Maryland.
Another example of innovation is the way many schools take their programs into the community. Harry Steadman, dean of continuing education at New York University, says his school offers 1,500 courses ``all over this town'' so they are convenient to people after work.
Alverno College, a women's school in Milwaukee, is one of many that have started special ``weekend colleges'' that enable adults to earn a degree in four years by attending classes two weekends a month. Birmingham Southern College in Birmingham, Ala., has a similar program that meets two nights a week from 5:30 to 10:20. Ten years ago, before starting this program, the school had 727 students. Now it has 1,726, a quarter of whom are nontraditional.
Determination, teachers say, is part of what lifts the adult classroom above its undergraduate counterpart. ``I don't see the commitment and delight in learning [in undergraduates] that I see in older students,'' says William Nicholas, a history teacher at Birmingham Southern. Diskin Gray, who teaches classics at Johns Hopkins, says his adult students are ``absolutely less inhibited.'' Undergraduates, he adds, tend to be preoccupied by grades.
``They [adults] are willing to challenge the instructor in class, which is wonderful,'' says Mr. Nicholas of Southern. ``I'm forced to rethink things I've been saying to undergraduates for years.''
``When we read Oedipus or Shakespeare, they'll say, `I've had this experience,' '' says Lucy Cromwell, who teaches English at Alverno. ``They are the most wonderful to teach.'' In addition, adult learners ``consistently have the highest grade-point average of all students,'' NUCEA's Mr. Brown observes.
On top of this, adult education is making pioneering use, for example, of new exams that measure what students have learned from life experience so they won't have to cover that same material in class.
But whether its Alverno College providing for Milwaukee women, or Maryland's University College preparing students for Washington's hot growth industry -- paralegal work -- community service is adult ed's guiding ideal.
Harvard may be a paradigm of exclusivity, but its extension school is anything but. A genuine Harvard degree in extension studies is available to virtually anyone willing to work for one. That is not a misprint. Pass four courses in the extension school (or two with honors) and you can become a bachelor of arts candidate at a Harvard program -- taught by Harvard professors at a fraction of the usual tuition.
``Thursday evening is the high point of my week,'' says Harvard's Mr. Mitten, speaking of his extension class. ``I get out of there feeling exhilarated.'' Mitten says his research has suffered from this extra teaching, but ``extension helps me feel I'm doing something for society.''
Would undergraduates benefit from rubbing elbows with older students in extension courses?
From schools that permit undergrads to take evening courses, or for extension students to sit in on daytime classes, the reviews are mixed. ``Younger students get impatient when older students ask questions,'' says Nicholas of Birmingham Southern. The undergraduates just ``want to sit there and take lecture notes.''
Others cite a more positive experience. ``I almost used to recruit [auditing students] from town to come to class,'' says John Chandler, president of the Association of American Colleges and formerly head of Williams College in Williamstown, Mass.
``Younger students would look to housewives for comments on the issues.''
In the 1970s, many universities seized upon adult education as their financial salvation. And just enough programs are run as ``cash cows,'' deans say -- with low-paid teachers and undemanding courses -- to give the snickerers ample ammunition. Even high-quality programs often face pressures to pay their own way that most English and history departments probably never experience.
To be sure, nontraditional students have prevented drastic drops in enrollments that some observers were predicting not long ago. Richard Bing, deputy vice-president of budget and planning at New York University, says the adult program there helps support some other programs that are ``academic powerhouses'' but don't pay their own way.
Over all, however, the expected bonanza ``hasn't panned out,'' says Richard Anderson of Teachers College at Columbia University in New York. Competition is too stiff, Mr. Anderson says. And adults simply aren't willing to pay the kind of tuition for evening courses that undergraduates pay for full-time studies.
Slowly, the stature of adult ed is increasing, nevertheless. Ten years ago, Mr. Hodgkinson of the council on education notes, the dean of continuing education was generally at the tail end of the receiving line at college receptions. Now, he says, that dean is ``near the front.''