Organized summer trips abroad for high school students took a nose dive in the wake of terrorism incidents that shook the transatlantic tourism industry two years ago. But this year tour organizers are looking forward to a booming teen-age market.

"We expect to do about three times as much business as we did in 1987," says Henry C. Kahn, president of the American Institute for Foreign Study in Greenwich, Conn., one of the largest U.S. organizations specializing in student travel. He estimates that as many as 150,000 American high schoolers will go abroad this year on one of a variety of educational programs.

"People have gotten over their fear of terrorism," he says. At the same time, his and other organizations are reassuring parents that their youngsters will be well looked after should new trouble erupt.

Perhaps 200 groups, both profit and nonprofit, put together student tours abroad. They include such variations as basic sightseeing trips lasting from one to six weeks; on-campus stays of several weeks to study a foreign language or other subject; home-stay programs where students live with a host family anywhere from a week or two to an entire school year; and enrollment in a college-level summer school for high school seniors.

Such trips are concentrated primarily in Europe, but some venture to Latin America and to the Orient. As an example of what a student trip might cost, a quick nine-day peek at historical England and Scotland is available at $950 to $1,150 per student, which includes air fare, lodging and most meals.

The value to students who can afford a foreign trip seems obvious. They learn at a very early age, says Kahn, that people in other countries think differently from Americans. Many students develop a new interest in the arts; others become fascinated with international politics. "A trip may change their career goals."

"There's a lot of value to it," agrees Monroe Davids, an eighth-grade geography teacher in Gaithersburg who has escorted student trips abroad for many years. "We have an absolutely wonderful time."

A more tangible reward is the boost it may give to a college admissions application. Says Kahn: "Students have told me they got into a better college because they spent that summer in France."

The next few weeks are among the busiest for tour operators as students begin confirming their summer plans. Some of the institute's most popular trips tend to fill by February or March, says Kahn. Tours, however, are offered during much of the year. Kahn's group sent 500 students to London for the week between Christmas and New Year's Day.

How do students and their parents go about choosing the right tour?

A practical start is to find out what is available, no easy task given the abundance of student programs. One good way is to find a copy of a 104-page booklet called "Advisory List of International Educational Travel and Exchange Programs, 1988." It is published by the Council on Standards for International Educational Travel of Reston, an organization set up by the student tour industry to establish standards for high school educational tours.

The booklet describes the programs offered by 36 tour organizers that it has evaluated and has found to meet its standards. The council requires that an organizer show financial responsibility and that its tours provide educational content. A tour organizer must advertise its programs accurately, screen applicants and provide students who are accepted with adequate health and accident insurance for the trip.

Among the entries are several home-stay programs; a number of summer foreign language courses; a leadership program for selected students; a program for volunteers interested in doing public health work in Latin America; a summer camp abroad; and the "Up With People" program for talented teen-agers who, if accepted, travel together for a year performing in an international musical show.

Some of these tour organizers provide scholarships or other travel assistance. Parents may also reduce the cost of a home-stay program for a child if they volunteer to take in home-stay students from abroad.

The fact that more than 150 other tour organizers do not appear in the booklet does not necessarily mean that they don't meet most or all of the council's requirements. As Linda A. Reed, the council's executive director, explains, the council evaluates only those organizers that request it, and many have not. The council was established three years ago.

Copies of the booklet may be available for use in high school career information centers or guidance offices. High school foreign language and social studies departments also may have the booklet. A copy can be ordered at a cost of $5 from the Council on Standards for International Educational Travel, 1906 Association Dr., Reston, Va. 22091, (703) 860-5317.

Once students have decided on one or more programs that interest them, they should send for more detailed information from the tour organizer. Kahn's American Institute for Foreign Study, one of the groups favorably evaluated, distributes a 100-page catalogue of its 1988 educational travel programs. The institute is a commercial firm.

As an example of what is available, here is a look at some of its tours and other programs:

Mini-tours: Nine- to 11-day sightseeing trips to the popular destinations of Europe. One called "Shakespeare & the Scots" takes the group to London, Oxford, Stratford, the Lake District, Edinburgh, York and Windsor. The trip is offered during most of the year. The price ranges from $929 to $1,159 per person, depending on the departure date, and includes air fare from Washington, hotel room with private bath, continental breakfasts and dinners. The institute also charges a $65 membership fee.

Traveling programs: Longer tour programs of 15 to 29 days in Europe, China and Australia and New Zealand. The 23-day "Classical Adventure" trip, departing June 29, visits Athens, Delphi, Mykonos, Rhodes, Crete, Sorrento, Pompeii, Rome, Florence, Pisa, the Swiss Alps, Paris and London. From Washington, the cost is $2,579 for air, lodging and most meals.

On-campus stays: Three weeks in a campus educational program and another week or two traveling. On the "Innsbruck Tyrolean Adventure," a 31-day trip, students spend three weeks studying the German language and culture (beginning, intermediate or advanced) at the University of Innsbruck. On the itinerary are visits to London, Amsterdam, Lucerne, Paris and Heidelberg. Departure is July 4. From Washington, the cost is $2,989 for air, lodging and most meals.

Home stays: Students stay in the home of a host family while attending school for a quarter term (15 weeks) or a full term (39 weeks). In France, the program is offered in La Rochelle, an Atlantic port about 300 miles southwest of Paris. Class offerings include French, which is required, and economics, French literature, history, geography and philosophy -- all taught in French. A full academic year, beginning Sept. 3, is $6,495 for air from New York, lodging and all meals.

The institute's traveling programs generally are escorted by teachers whose expenses are paid if they recruit a group of six students. The institute also assigns a trained tour manager, who remains with the tour on a 24-hour-a-day basis. Applicants who contact the institute will be given the name of a teacher in their school or in the nearest community who is accompanying the desired tour.

A teacher with six or eight students from one community, says Kahn, will join similar groups from other regions of the United States to fill a motorcoach. This means a group of 30 or so students may be escorted by several teachers as well as one or more tour managers. The institute says it tries to assign students of the same age level to a tour.

The tours stay in three- and four-star hotels, and rooms (generally for two) have private baths. Students are expected to adhere to a written code of conduct that includes a nightly curfew and a requirement that they participate in all excursions and field trips that are a part of the stated program. In breaches of discipline, the student may be restricted to his or her room during leisure time, be required to contact parents by phone to explain the difficulty or be expelled from the tour and put on the plane home.

Such discipline problems occur infrequently, says Kahn.

To reassure parents, the institute promises it will cancel any tour to a country where the U.S. government, through its system of State Department travel advisories, cautions against travel by Americans. Should such a warning be issued while a trip is in progress, the institute will escort the tour out of the country at its own expense and arrange for an alternative itinerary.

For information about these and other institute programs, contact: American Institute for Foreign Study, 102 Greenwich Ave., Dept. P-1, Greenwich, Conn. 06830, (800) 727-AIFS or (203) 869-9090.

Teacher Monroe Davids acknowledges that choosing a good travel program can be difficult. Though a first-time traveler abroad is tempted to try to see everything, he recommends choosing a tour that specializes in one area. Some tours, he says, "go too many places. You don't see anything. I don't want to be on the bus all the time. I want to get out and walk through the streets."

Students and their parents should also determine how serious the tour organizer is about providing educational content. Much depends, of course, on the tour escorts. Davids recalls a trip to Vienna where the tour group found out about a special museum exhibit. He took his students to see it. Another teacher opted for a shopping excursion.

Another point Davids considers very important is what sort of evening activities are planned -- concerts, movies, bowling, for example. Many organizers, he says, "do not plan things at night for the kids, and that's really a negative."

In its booklet, the Council on Standards for International Educational Travel also offers some helpful guidelines. It suggests parents and students determine:

That the tour escort is familiar with the language, culture and customs of the country to be visited.

That free time, when students are on their own, is not excessive. "Different customs, culture shock, even homesickness," says the council, "greatly increase the need for the constant presence of a wise and understanding counselor, not merely a chaperon."

That the screening process of students is adequate. The council advises that tour organizers obtain letters of recommendation from school officials and other sources. "Not every high school student is ready for a travel/study program abroad, away from parents and family in a partially unsupervised setting. If a program accepts anyone who applies and pays the fee, you should seriously question its overall merit."

How competitive rates are with other tour organizers offering similar programs. Other financial concerns include refund policies, insurance and necessary travel expenses not covered by the basic tour fee.

CYCLING THE SOVIET UNION: Could it be a result of the Washington summit? The Soviet Union has just granted permission to Open Road Bicycle Tours of Haymarket, Va., to lead a 19-day cycling trip from Moscow north to Leningrad and Helsinki, Finland.

"We've been trying for two years to get permission to bring tours into the Soviet Union, but we kept running into a stone wall," says director Byron Reed. "Now, the Washington summit has turned things around, and we're very excited about going."

The inaugural departure is June 11, and Reed, whose firm has offered cycling trips to China for several years, is pursuing plans for a subsequent trip later this year.

One drawback is that Soviet officials so far are requiring that the tour -- limited to 20 participants -- stick to authorized motor roads. But Reed is working to ease that restriction, so the group can explore back roads.

The group flies to Moscow, cycles to Helsinki and returns to Moscow by train for the flight back to Washington.

Participants will stay in hotels, and their luggage will be carried in accompanying vehicles. Reed estimates the tour will cover about 30 miles a day by bicycle. However, because of the distances between cities, some travel will be aboard the group's bus. A truck will carry the bicycles.

The cost is $3,799 to $3,875 per person (double occupancy), depending on departure date. Included are air fare from Washington, lodging, meals and bicycle rental. Serving as translator will be a Russian-speaking American businessman who is based in Vienna and travels frequently to the Soviet Union. For information: Open Road Bicycle Tours Ltd., 1601 Summit Dr., Dept. S, Haymarket, Va. 22069, (703) 754-4152.

An alternate two-week itinerary is being offered, also for the first time, by International Bicycle Tours of Chappaqua, N.Y. The route is from the Russian town of Brest on the Polish border via Minsk and Smolensk to Moscow. Participants fly to Poland, take the bus to Brest and fly home from Moscow.

Departures are June 12, Aug. 8 and Aug. 22. The land cost, including bicycle rental, is $1,850 per person (double). Air fare is additional. For information: International Bicycle Tours, 12 Mid Place, Chappaqua, N.Y. 10514, (914) 238-4576.

ISRAEL AT 40: To celebrate the Israel's 40th anniversary this year, the Smithsonian Resident Associate Program is offering an eight-session course on Israel today. It concludes with a reception at the Israeli Embassy and a talk by Ambassador Moshe Arad on the state of U.S.-Israeli bilateral relations.

The 90-minute sessions will be held Wednesdays at 6 p.m., Jan. 27 through March 16. Topics include "New Archaeological Discoveries," "Israeli Economy in Transition," "Israel as a Melting Pot" and "Israel and the Middle East: A Geopolitical Analysis." The latter will be led by Haim Shaked, professor of modern Middle East history at Tel-Aviv University and professor of Middle East studies at the University of Miami.

The fee for resident associate members is $80. For nonmembers, it is $110. For registration: 357-3030.