I think of "teaching to the test" as meaning teaching mostly by rote memorization, instead of teaching the underlying concepts. In other words, the teacher basically lays out exactly what's going to be on the test, and that's what you get tested on. That's fine for some subjects sometimes, but doesn't teach analytical thinking. A common example in the IT field is people who have passed the Microsoft Certified Systems Engineer (MCSE) test, but when faced with an actual problem on a network, have no clue where to start troubleshooting. It's to the point where MCSE certification really doesn't mean much, because so few of the people who hold it deserve the title of "engineer." And I think when people complain about school teachers "teaching to the test," what they mean is that people are earning diplomas by learning a given set of facts, but aren't learning the skills they need to succeed in the real world.