THE SIZE OF THE GAPS: From bottom to top!

TUESDAY, JUNE 3, 2014

Part 2—Porter’s portrait confirmed: Could Eduardo Porter’s portrait of our schools possibly be accurate?

Two weeks ago, Porter devoted his Economic Scene column to a somewhat formulaic treatment of our public schools. Porter isn’t an education specialist. After reading his column, we’d have to say it showed.

Still, Porter painted a very striking portrait at one point in his piece. We’ll return to the question we asked last week:

Can the highlighted claim possibly be accurate?

PORTER (5/16/14): Tracking also happens within schools, where students are often separated by ability. “Advanced children are all put together; they all know each other and learn from each other’s habits,” said Sal Khan, the founder of the Khan Academy of on-line education. “At the low end, it’s an educational wasteland.”

Addressing the vast disparities between students’ abilities will not be easy. In some public schools, children who are entering the sixth grade with the measured proficiency of first graders are mixed in with children who perform well above the sixth-grade standard.

Schools struggle to teach this mix. Teachers are frustrated: Almost half leave the profession within five years.

Can that possibly be correct? According to Porter, some middle schools struggle with an amazing range of achievement levels. Some sixth graders have “the measured proficiency of first graders,” he says. Other sixth graders in the same schools are performing above sixth grade level!

Almost anyone can see the challenge this wide range of achievement levels would likely present to a school. With even a small amount of imagination, a person might even ask an obvious question:

If sixth graders display this very wide range of achievement levels, what role can a set of grade-level “standards” possibly play in the life of a school? Forget about the Common Core, the current focus of widespread dispute. How can any set of grade level standards address the “vast disparities” described in Porter’s portrait?

We’ll leave that obvious question for another day. That said, we’ve never seen that question asked in our major newspapers, and there’s an obvious reason for that:

In the main, these newspapers exist to spread elite propaganda about the state of our schools. They exist to discuss the gaps, not the gains.

They exist to spread the idea that achievement levels in the schools are stagnant or declining. And, for the past several decades, they have happily talked up the role of grade level sets of standards.

Not for them, the basic facts about the large score gains our schools are recording! Not for them, the obvious question about the way grade level standards are supposed to work!

That said, large achievement gaps exist within our public schools. Today, we start to sketch the size of the gaps.

Is it even dimly possible that Porter’s portrait is accurate? Do our middle schools really “struggle” with such a remarkable “mix?”

Porter didn’t say how he knew that some schools contain the “vast disparities” he described. He didn’t say how many schools face such daunting gaps.

That said, data from the National Assessment of Educational Progress (the NAEP) let us start to define the size of the gaps within our national student population. Returning to Grade 8 math as our basic field of study, here are some scores from the most recent administration of the so-called “Main NAEP:”

Average scores, Grade 8 math, 2013 NAEP
90th percentile: 331
75th percentile: 310
50th percentile: 286
25th percentile: 261
10th percentile: 237

For all such NAEP data, click here. You can examine the range of scores in reading and math in Grade 4 and Grade 8.

Eighth-graders recorded a wide array of scores on last year’s NAEP math test. At the 90th percentile, students scored 331. Students at the 10th percentile scored almost 100 points lower!

On their face, those scores suggest a very wide range of achievement levels.

As we’ve often noted, a very rough rule of thumb is often applied to NAEP scores. According to this very rough rule of thumb, ten points on the NAEP scale is compared to one academic year.

In yesterday’s report, we saw Stanford professor Sean Reardon applying this very rough rule of thumb to some scores from the NAEP’s Long-Term Trend study. Applied to these Grade 8 math scores, that rule of thumb suggests an astonishing range of achievement levels.

Among eighth graders, could there really be a nine-year achievement gap between students at the 90th and 10th percentiles? For ourselves, we will assume the answer is no. Data like these help explain why we always describe the ten-point rule as a very rough rule of thumb.

How large is the achievement gap among our eighth grade students? Such questions are almost never explored in the national press, which mainly exists to publish propagandistic sound-bites about the public schools.

The nation’s “education reporters” will happily chatter about the role of the Common Core, or other grade level math standards, without presenting or confronting such confounding statistics. Most likely, our education reporters have never clicked through to the data which display this very wide range of scores. In our Propagandistic New World, it simply isn’t done!

Among the nation’s eighth graders, how large is the range of achievement? We’d love to see that question discussed! We were thrilled to see Porter introduce the topic, which is extremely important.

NAEP scores can only provide so much precision. But at least on face, Porter’s portrait isn’t challenged by these confounding NAEP statistics. These data seem to suggest that the achievement range among eighth graders is extremely large.

Tomorrow, we’ll start to look at the way these gaps break down by income and race. For today, let’s add one point:

According to the NAEP data, students at the tenth percentile are doing substantially better than their counterparts did in years past. In 1990, the first year of the Main NAEP study, the tenth percentile score in Grade 8 math was 215. Last year, students at the tenth percentile scored 237.

A substantial score gain has occurred at the tenth percentile. That said, the gap in scores remains large; a slightly larger gain has been recorded at the 90th percentile.

Unless something is grossly wrong with this widely-praised “gold standard” testing program, substantial academic gains seem to have occurred in Grade 8 math. But the gaps seem to remain quite large—and, as Porter suggested, large gaps present very large challenges for our public schools.

Where do these large gaps come from? Tomorrow, we’ll look at the way the gaps in scores align with family income.

Tomorrow: Size of the gap by income