We say it all the time. Parents say it, teachers say it, counselors say it a lot: go research colleges. We know that choosing one out of thousands of American community colleges, liberal arts colleges, universities, art schools, research institutions, and technical colleges takes research on the part of the applicants. But what exactly do we mean when we say research? And how do you do it? Let me try to explain.

First: What are you even looking for? When you’re researching, you’re looking at three categories that often overlap, what I call fit, numbers, and vibe. Fit is a good place to start.

Fit is a word we use a lot in college admission, usually in a vague way about finding the schools that are best for you. I’m using fit here to mean the things that are important to you in choosing a college, are not as precise as a statistic you can look up, but are more easily managed than the general feeling you get from a school. Here’s what to consider when thinking about fit:

You should probably think about the size of college you’d like. While many students have no preference, most at least think they might do better at a small, medium, or large school—even if they don’t know what counts as small, medium, and large. The more interactions you have with colleges of different sizes, the more you’ll get a feel for what size is right for you.

Look at a college’s listing of the majors they offer. Look through the list on their website. This is really important. For one, if you just search “does ____ have a ____ major?” then you might find that the answer is no…but that they really do and just call it something different. Also, looking at lists of majors may introduce you to fields you hadn’t considered before or hadn’t even heard of. And, the list of majors gives you an idea about the depth of a certain department. For example, there are colleges with one or two engineering degrees. And there are schools with 12 or more engineering degrees.

Look at the college’s social and religious affiliations and try to understand how they shape the school culture. A religious name and sponsorship doesn’t necessarily mean that the college has an overtly religious agenda or creed. But you may want to look into it. The religious affiliation with the school may or may not have some effect on the student population. For example, Notre Dame is a Catholic university, and around 80% of its students identify as Catholic. Loyola University of New Orleans, also a Catholic university, is less than 40% Catholic.

See what sports and other major activities the college offers, even if you don’t plan on playing sports. Look up their Greek Life (sororities and fraternities) culture and see how many students are involved.

Think about how close to home the college is and how easy it is to get there. If it’s driving distance, how long will it take you to get there—especially if you don’t have a car? If it’s farther away and you’ll be flying, is it a non-stop flight from your local airport? And once you land, how far of a drive is it? Get a feel for how easy it is to get to and from school, not just the distance in miles.

Consider weather and climate of the area. How comfortable are you with cold? With heat? With rain and cloudiness? Those things matter.

How important is campus safety to you? That definitely matters. Overall safety is difficult to measure and compare, but you should look into it.

So fit includes the general things you’re looking for. It’s what goes into a college mission statement. When you know what you’re looking for, you can start looking up hard numbers to see how well schools fit what you want.

What numbers to look at:

Definitely look the size of the school, measured in the number of undergraduate students. Think of around 3,000 undergrads and fewer as small, 15,000 or more as large, and everything else as medium. Those are just generalizations, but a nice starting place.

Look at the retention rate of the school, which is the percentage of first-year students who come back for their second year. Look at the graduation rate, which is the percent of students who are able to graduate with a degree within six years of starting. (The national median graduation rate is in the mid-60s range.)

Look at the school’s acceptance rate, which can be as low as 4% or as high as 100%. Around 75% of colleges have an acceptance rate of 50% or higher. Look at the gap between acceptance rate and graduation rate. A school with an acceptance rate of 25% and a gradation rate of 85% is choosing top candidates and moving them on to graduation. A school with a graduation rate of 85% that accepts 50% of applicants is choosing far more candidates…but still moving them on. That’s a good sign.

Look at their financial aid numbers, especially the percent of need met, the average net price, and the average debt at graduation. You never know what an individual college will cost you until you apply, are accepted, and are given a financial aid offer. But you can start to get a sense and to compare schools by looking at these averages.

Fit considerations are based on the numbers you look up, but they also encompass things beyond stats. Vibe—or general feeling or culture—is even more vague. But it’s often just as important.

The best way to get a sense of the vibe of a school is to visit it while students are there. But that’s not the only way, so don’t feel like you can’t get to know a school’s general atmosphere without being there.

You can look at a college’s rankings (like on Niche, for example) for non-academic categories: student life, dorms, food, campus, and party-school reputation. Spend time looking at the photos and videos on a college’s website and see how well they match your expectants of college (but warning: they can all look alike at first). Take advantage of any virtual tours that are available online. Spend time wandering around the college’s website. Email the admission department and ask them if they can set you up with a current student who can answer your questions about the school’s culture and vibe.

Those are the three things you’re researching. Here’s something really important: the research process is circular. You look at the numbers to find colleges that match your preferences for fit, and then you check out their vibe. But after you learn more about the possibilites, you may decide you want to change your preferences for fit…which will have you looking for different numbers…and finding new places to check for vibe…which may have you reconsidering fit….

Looking at a few colleges will give you a better sense of what you want, which will help you find some more schools to look at. I wouldn’t recommend choosing your college solely on a vague sense of vibe, nor would I recommend choosing one solely on numbers in a spreadsheet.

What is your ultimate goal? What you want is a balanced list of colleges you’re going to apply to. It should be four to 20 schools. When I say balanced, I mean balanced in terms of acceptance rates, fit, and finances. Find at least two colleges that meet your general fit requirements and where you’re also very confident you’ll be accepted and can afford. (These are often public universities close to home). Once you have those settled, start looking at schools that also match your fit, maybe even better, but that you’re less confident about admission success. Understand that once a college’s acceptance rate gets below around 25%, absolutely nobody can feel confident about being accepted no matter how strong their application. Don’t be afraid to apply to these schools, but don’t make them your top priority.

Don’t be in a rush, and be open to change. I like the list to be around 20-30 by end of junior year, and then reduced to 4-12 by application time.

Where do you look?

Let’s start with the easy. A quick Google search is an obvious—and not bad—place to start. Your search will probably include the word “best.” Best colleges to study sports management. Best colleges in Ohio. Best value colleges. These types of searches are fine places to begin to get a feeling for what’s out there. You don’t want to stop there, but it’s a good start. Just don’t get too caught up in the rankings themselves. Number 14 is probably not significantly different than number 4. For many categories, I try to think as the top 100 as tied for first place.

There are several online sources for solid college profiles. I tend to use BigFuture, which is published by the College Board, and Niche the most.

Online you can also use Princeton Review, US News, MONEY, and Wall Street Journal. These may require you to set up an account or to pay for some features.

My absolute favorite guide, and the favorite of most the admission professionals I know, is the Fiske Guide. It’s not online; you’ll need to find the book. It’s worth the money and effort.

You can also find all sorts of great information on individual colleges’ websites, their social media accounts, and the information they send you once you sign up for their mailing list, which you should do if you’re interested in a school.

There’s also online forums like Reddit, which I frankly almost never use. If you do, just remember not to put too much weight into any single person’s opinion.

One of the best places to get numbers about a college is from the college’s Common Data Set.

And, of course, don’t forget about your school counselor—if you have one—and the counseling office.

The three most common factors I get from students searching for colleges are major, size, and geographic region. If you already have a preference in these three categories, then the initial search can be pretty simple. If your major is rare or niche, then that’s going to limit things. If it’s something really common that most colleges offer, like Biology or Political Science, then that’s going to make the initial list longer. Same with how narrow or broad your geographic preferences are. If that initial list is longer than 35 schools (and it probably will be), then start doing some narrowing down.

This is when you have to start thinking about balance. Don’t have more than 5-7 schools with acceptance rates under 25%. Make sure you have at least two with acceptance rates over 70%. Look at their locations within your geographic area and think about which ones are most appealing. Look at average net prices and make sure most of your list is in a range that feels comfortable for your family. Consult some “best of” lists or rankings to see which ones have better reputations. Get that list down to 35 maximum. Then, it’s time to start doing deeper dives by looking at their numbers and checking on their vibe. Go through the circular process of fit, numbers, and vibe. Don’t be afraid to make changes, but understand that by application time, you’ve got to get that list down to 20 maximum, and preferably more like 12.