All of us have done it. All of us have had it done TO us.

I'm talking about ratings.

The boys in my undergraduate dorm laughed at their ratings of the coeds in the cafeteria line -- placards held high with the numbers.

Those same boys cringed when the coeds rated THEM that evening at dinner. The women added ... comments. (Which just goes to show you, said the boys, how cruel and unfair women can be.)

It takes a while in life to learn important lessons. Here's one of them: Rate not, lest ye be rated.

Here's another. The rating is only as good as the people doing the rating -- and the standards they use to get there.

When I was young, I was often devastated by other people's negative judgments about me. These days, it only matters to me if I respect those people, and their knowledge. If I don't, who cares what they think?

Even if I do respect them, I've learned that nobody's judgment of my behavior is anywhere near as demanding as my own.

In the library world, there seem to be just a couple of ratings that matter. One of them is decidedly local: community support.

Community support for a library can be evaluated in several ways. The obvious one is use. Lots of people have library cards, or check things out, or attend library programs, or use the meeting rooms or Internet computers.

Another measure of community support is equally obvious: money. Some libraries win their bond or mill levy elections. They successfully lobby their cities or counties to get their annual appropriations. As a result, they have more books and buildings.

Yet another measure of community support might be the library's reputation. Do most people in the area respect the institution and its staff -- or hold them in disdain? Or worse, what if the community doesn't think of the library at all?

After the local community, the second big rater of public library service in the United States is something called the Hennen American Public Library Ratings.

If you've lived in Colorado for a year or more, you've probably heard of this. Denver Public has for a couple of years now been rated first in the nation for its population served (over 500,000).

Hennen, as it happens, is just some guy in Wisconsin (he does run a library system) with an interest in statistics. Almost as a hobby, he started using various stats on public libraries to come up with a list of libraries that were the "best."

Mostly, his ratings are based on a combination of things mentioned above: checkouts per capita, square feet of library space per capita, and expenditures (especially for books) per capita. It may not be complete, but it's all pretty reasonable.

Hennen has also been very successful in marketing his index in both the library world and the popular press.

There's about an 18 month lag in his ratings. So they are always a little behind the times.

For instance, he just published his latest index. Denver Public again won in its population category. The rating does not reflect the deep cuts Denver sustained the past two years. It won't win next year.

But guess what? Also appearing in this year's index of the top 100 is the Douglas County Libraries (still called Douglas Public Library District, since the data are based on two years ago).

In the 100,000 to 249,000 population category, your local library is rated number 3 in the whole United States. That's right. We're third best in the country.

I am, as all my friends will tell you, a truly gentle man, far more interested in collaboration than competition.

But let me say this.

Naperville Public, IL and Medina County District Library, OH -- watch your back! You're going down.