No one wins when states hold their K-12 students to a low bar, but it is low-income and minority students who suffer the most. Low expectations can conceal just how far such students lag behind their peers and dampen the urgency of raising their performance.

Last week, we demonstrated how dramatically those achievement gaps grew in five states that made their tests harder to pass. Well, here’s a sixth state. On January 29, Texas released the results of the tougher math test it debuted in 2011/2012. Note what happened to achievement gaps after the new test went into force. (The white/Black achievement gap would be 10 percent if 50 percent of white students and 40 percent of Black students passed the state tests)

Gaps in the Percentage of Students Passing the Texas 4^th- and 8^th- Grade Math Tests, by Race/Ethnicity and Income

So what lessons should we draw from this doubling of gaps? Here are a few:

• Educate yourself. Official data on achievement gaps can be very misleading, especially in states whose tests focus mostly on basic skills or have low “cut scores”—the scores students need to pass. Such tests aren’t very sensitive to big differences in students’ knowledge or skills. (Find out more about where your state sets the bar in math or science.)
• Brace yourself. If your state sets a low bar, get ready for a shock when that bar goes up. No group of students will fare well, but the passing rates of low-income students and students of color may fall the farthest.
• Be vigilant. States are planning big changes, but they could backslide. The vast majority have adopted common standards for academic content in K-12 and are designing common tests of that content. They will have to set common cut scores in the next couple of years, and wonks the nation over will be watching closely. Check in with us or other experts to see if the new cut scores reflect real-world demand for knowledge and skills rather than political timidity.)
• Be patient. Some critics will seize on plummeting passing rates and widening gaps as evidence that schools are in decline. That’s just not true. It is true, however, that schools have improved too slowly. Better state tests can offer better markers of progress.

The stakes of this discussion could hardly be higher. Many breathless claims about "what works" in education rest on state tests that might obscure at least as much as they reveal. New, more challenging tests could be the start of a whole new ball game. Let's hope so.