Q: My neighbor's daughter is a first-year student at a large public university, and it seems that most of her instructors are graduate students. She has met few actual professors. Now we are starting to look at colleges for our son. I want him to be taught by experienced professors—but does that mean he must attend only a private college? Those schools are so much more expensive!

A: It all depends upon the school. Part of the answer is in the vocabulary you use: university and college. A university has an undergraduate program and also graduate programs. It is very common for experienced graduate students to teach introductory classes in many departments. More advanced courses should be taught by full-time, permanent members of the faculty. But schools should not use graduate students or other part-time faculty to teach a majority of classes. You will have to do some serious research to learn if this is the case.

It may shock you to learn that private undergraduate colleges do something similar, even though they do not have their own graduate schools. But there may be a nearby university whose graduate students they can employ, or other qualified individuals they can hire at salaries much, much lower than those of full-time professors. So paying the higher tuition and fees for a private college is no guarantee that your son will be taught by professors. Your tuition dollars will be used instead to subsidize the school's other projects.

Here is a real example, though of course I cannot mention the name of a specific school.

A private college in a rural, but exciting, area has been growing in popularity. It is quite expensive, but offers many scholarships and other inducements to enroll. The campus is beautiful, with many new buildings. Nearly half of its teaching staff—over 40 percent—is part-time, or "contingent" faculty. This means that instructors are paid $1,500 per course, per semester. For a semester's work, including preparation for class and grading papers, that is very, very low pay. And being part-time means the college does not have to pay them benefits, such as health insurance.

Why do people accept these working conditions? Because—this is especially true of academicians at the start of their careers—they want to add a line on their resumés that they taught at this college. Maybe this will help them get a better job down the road. And many need the extra money; $1,500 is not much, but it is something.

So why is the price tag for this school so high? Because tuition has to subsidize the new buildings, the athletic facilities, the landscaping and the high salaries of college administrators.

And where does the college find its labor supply in this rural area? There is a large university nearby. The overuse of underpaid instructors generally occurs in two geographical areas: 1) college and university communities that are far from urban areas, but where a highly educated population is abundant, and 2) urban areas where the labor supply is huge.

Schools will exploit part-time teachers generally for two reasons: they are strapped for funds or they need to save money for other things. Unfortunately, the practice will not decrease in the future. Each year, there are openings across the U.S. for full-time, tenure-track or tenured professors. But most academic jobs now and in the future will be part-time. Just leaf through articles and job postings in the Chronicle of Higher Education and you can see for yourselves.

Back when I and many others reading this column went to college, campuses did not have to be gorgeous. The dorms ranged from so-so to shabby, and cafeteria food was bad. Schools did not advertise; if you wanted to apply, you applied. It's all different now. Campuses are lushly landscaped, there is gourmet food in the dining halls, dorm suites are nicer than many apartments. This all costs a lot of money. And those slick, multicolor brochures you are receiving in the mail? The tempting website? Expensive.

This explanation does not help you find out where your son is more likely to obtain a quality education. You will need to do some research.

Every school must fill out a form called the Common Data Set. This is done fresh every year. The CDS tells how many people applied, how many were accepted, how many are male, how many female and so forth. It also tells how many faculty members there are, how many male, how many female, how many full-time, how many part-time. If you see that more than 30 percent of the faculty is part-time, that's a red flag. If the figure is 50 percent or more, that is a clear danger sign. I suggest you talk to current students and ask them about who their teachers are, how often these teachers are available after class and get their general satisfaction with the classroom contact they experience.

There is no perfect or definitive answer. Some part-time teachers are better than some tenured faculty. Some large classes are more exciting than smaller ones. Going to an expensive private college is no guarantee of finding inspiring and devoted professors, because you can find these individuals at large state universities as well. But now at least you know the questions to ask!