Beware of rankings.

Two recent stories highlight the problem with these pronouncements.

Putting together a ranking is an easy way to grab a headline, and when the rankings are about things such as favorite beaches or best movies they can be a fun subject for conversation.

But when rankings are about important things, such as crime or education, they can range from pretty useless to downright misleading, especially if you don't know what agenda the group behind the ranking is trying to push.

That was the case this week when a group called StudentsFirst gave New Jersey a "D" on its State Policy Report Card.

Ouch. New Jersey schools do a worse job than those in the top-rated states in the report, Louisiana and Florida?

Well, no. New Jersey schools are actually among the best in the nation, and this report has nothing to do with their effectiveness in teaching students.

There is nothing in the report about test scores or graduation rates or the percentage of high school students who go on to college - all measures by which most New Jersey schools are doing a fine job.

Instead, the report is entirely concerned with policy initiatives being pushed by StudentsFirst, a group headed by Michele Rhee, former Washington, D.C., superintendent with a controversial ax to grind. The group's mission is to support changes in state laws that weaken teacher unions, promote vouchers and make it easier to open charter schools. So the purpose of this press release disguised as a report card is really to manufacture a sense of crisis to help move that agenda along.

None of that comes across, of course, if you just read a headline somewhere or hear a sound bite that says "New Jersey schools get a 'D' on report card."

The same problem occurred for a different reason when a website called Neighborhood Scout ranked Atlantic City the seventh most dangerous city in America.

As police officials were quick to point out, the website came up with that ranking by committing a sin familiar to resort towns - it divided the number of crimes by the year-round population. By ignoring the millions of annual visitors, this faulty math produces a distorted crimes-per-capita figure.

If you didn't know better - and the people behind Neighborhood Scout apparently don't - you'd get the impression that Atlantic City is a more dangerous place to be than Newark or Chicago.

This is nonsense, of course. Such undeserved bad publicity is the last thing Atlantic City needs.

Yes, there is a troubling amount of violence in some of the city's neighborhoods. But that is no excuse for misrepresenting crime statistics to make things seem worse than they are.