AS AFRICAN ART expert Roscoe Thompson tells it, he could barely believe his eyes. There he was, having slogged his way to the interior of deepest, darkest Mali, and there it was, a daisy-fresh group of clubwomen from Milwaukee on a package tour.

Well, not all tour-takers will wind up in Africa this winter -- or Vegas, Cancun or Honolulu either. Some, in fact, may not make it off the ground. Tour operator bankruptcies and closures are a big reason. Reportedly about 10 percent go under each year. A number do it spectacularly, leaving paid-up clients without tours and without refunds.

In many instances, travel agents have made good the amounts lost. But since they're no keener than anyone else about giving away what they've worked for, they've been casting around for a way to protect themselves and their clients.

One of the latest efforts, a bonding plan to insure that purchasers get either their trip or their money if virtually any of the 350-400 U.S. tour companies should fail, has itself failed. Other proposals are expected to be introduced, and some major tour wholesalers do have various amounts of financial backup. But the need for more is widely felt and regarded as vital, if not critical, in today's market.

What's startling, though, is the fact that the tour business has grown so large with so little in the way of guarantees. Of course, it might be considered equally stunning that anyone at all would buy a product that's sold as "carefree and convenient," pay in advance, and then accept fine print that allows the seller to later charge a few things -- like the price, the dates, the itinerary and the hotels.

This is, indeed, what most tour contrcts permit. At least one tour group that left for Guatemala is known to have wound up in Mexico. Each winter, too, there are screams of rage from travelers who bought tour packages because of their deluxe beachfront accommodations and got trundled to second-class lodgings miles away. In many cases, the tour operators rightly cry that it's not their fault, that things happen that are beyond their control. Obviously that's the case -- yet tours are represented as the "safe" way to go.

Package tours sell for a variety of reasons, not the least of which is that many travelers believe they represent a saving over what the components would cost if bought separately. Some do, some don't. It often depends on how you define "saving." You may be buying "discounted" high-cost items when lower-cost versions are available and practical. You may be buying a "full" package which, besides the essentials, contains things you don't want and can't use.

You may also be paying built-in service charges for having the whole trip put together for you or for an itinerary or services you'd be hard-pressed to get any other way. Occasionally, even "bulk" buyers get no better rates than individuals; indeed, some group air fares are higher than some publicly available promotional fares.

However, packages also sell for a sounder reason: Despite the fine print that they hope gets them out from under, most tour operators appear to deliver what's promised -- and a high percentage have been doing so for 20 years or more. The trick, then, is to pick the roses while avoiding the thorns.

Basically that comes down to three things: figuring out what you want, asking the right questions and getting sound advice.

The first part involves sorting through the options. For instance: Do you want a large group, a small group, no group? Full-time guides, part-time guides, no guides? Many destinations or a stay-put trip? Do you like lots of scheduling and lots of features included in the tour price, or a barebones package that leaves everything optional but dates, transportation and accommodations? Package tours, of course, range from weekend hotel stays to months-long climbing expeditions. Some, by their nature, make a lot of the what-I-want decisions for you.

In your questioning, though, you might bear in mind that complaints have centered on:

Changes in hotels and schedules;

Cancellation penalties alleged to be unreasonable;

Price increases after purchase;

Claims of misrepresentation in the quality of tour components;

Failure to provide all of the items advertised;

Slow refunds on canceled tours;

Lack of care and compensation in delays;

Runarounds when trying to fix responsibility for something that's gone wrong.

Some upsets are traceable to the customer's misunderstanding what is or is not promised. The best clue to what's included is the brochure that describes the tour. Yet some brochures raise more questions than they answer, and assumptions can get you in hot water. Is "breakfast," for example, what you're used to or something quite different, and does a "morning " tour mean up at 5 or up at 9?

Enter the travel agent. Travel agents, even if they haven't been where you want to go, should know how to get the answers you ask -- for free. If you point to a par of look-alike tours, one priced at $700 and the other at $800, it's the agent's job to be able to explain the difference. If one can't do it, keep moving until you get an agent who can.

A travel agent who's clearly on your side will try to draw you out to find out what you understand and to answer questions you might not know enough to ask. Strain yourself. Ask an extra ton of questions about tours with super-low rates, and just as many if you come across someone who has a display of cheapie tours but quickly presses you to buy something "better." Whatever you do, don't sit there keeping your likes, dislikes and financial limits all to yourself.

Presumably your likes include both taking the trip and enjoying it. If so, there are several questions that you should ask a travel agent about a tour before you pay a penny:

How does your agency check out tour operators for performance and financial stability?

What kind of financial guarantees does the tour operator offer?

Is departure guaranteed or can it be canceled for things like lack of participants? If so, what is the tour's status now? If it must be canceled, how much notice do you get and what happens then?

Has anything about the tour changed since the tour brochure was published? (And, in particular, is the price now guaranteed, or how late in the day can it be changed?)

Under what circumstnces do you have to pay a penalty if you cancel or have to leave the tour? (A good agent will explain your insurance options.)

There are more than 57 varieties of answers to these questions, and in the end, it's up to you to decide if you can or can't accept them.