In reading, 12th grade scores remained flat, continuing a trend since 2009.
Perhaps the most striking detail in the test data, though, is that the lowest achievers showed large score drops in both math and reading. Between 2013 and 2015, students at or below the 10th percentile in reading went down an average of 6 points on the National Assessment of Educational Progressthe largest drop in a two-year period since 1994. The high achievers, on the other handthose at or above the 90th percentiledid significantly better in reading, gaining two points, on average, while staying stagnant in math.
"In the case of reading ... students at the top of the distribution are going up and students at the bottom of the distribution are going down," said Peggy G. Carr, the acting commissioner of the National Center for Education Statistics, which administers NAEP, during an April 26 media call. "I think that's something we need to think about. ... This is a pattern we're seeing in other data."
As for the mathematics average score, "I think the decline is real," she added.
A nationally representative group of 13,200 12th graders took the NAEP math test in 2015, and 18,700 took the reading test. NAEP, which is administered periodically to different grades and in different subjects by the National Center for Education Statistics, is considered a barometer of U.S. students' achievement. This year's 12th grade results do not include state-level data, Carr explained, due to funding constraints.
In math, the average score was 152 on a 300-point scale, which was nearly two points lower than the 2013 average and constituted a statistically significant decrease. In reading, the average score was 287 on a 500-point scale—statistically similar to the average score two years ago.
Looking longitudinally, math scores are statistically similar to those in 2005, the first year that's valid for comparison. Reading scores have declined since 1992, when the test was first administered.
When the scores are disaggregated by low, middle, and high performers, it's clear that the low-performersthose at the 10th and 25th percentileare scoring much lower than they did two years ago. That may be in part due rising graduation rates, said Carr. (The national on-time graduation rate hit an all-time high of 82 percent in 2014.) "The dropout rate for all students has improved," she said. "That means we have students who normally would not be there who are there."
( Chart below: 12th graders' math and reading scores by low, middle, and high-performing students. )
Results for NAEP, known as the Nation's Report Card, are also reported at three achievement levels: basic, proficient, and advanced. "Proficient" indicates students are successful with challenging, grade-level content.
Twenty-five percent of 12th graders scored at or above the proficient level in math. That includes the 3 percent of students who scored at the advanced level. In reading, 37 percent of seniors scored at or above the proficient level, with 6 percent scoring at the advanced level.
The percentage of students scoring below the "basic" level was significantly higher in both reading and math than it was two years ago. It went from 35 to 38 percent in math, and 25 to 28 percent in reading.
Starting in 2013, NAEP also began reporting on the percentage of students who are considered academically prepared for college, meaning they should be able to do first-year college work without needing remedial courses. To reach that threshold, students had to score at least a 163 in math and a 302 in reading.
In both reading and math, just 37 percent of high school seniors scored at the college-ready level.
"The governing board is pleased that graduation rates are increasing across the country, but at the same time we are not making the progress we need to for post-secondary, work, and military participation," said William J. Bushaw, executive director of the National Assessment Governing Board, which sets policy for NAEP. "We have to redouble our efforts to prepare our students and to close opportunity gaps."
The data also show that large racial and ethnic achievement gaps have persisted. White and Asian students continue to significantly outperform their black, Hispanic, and American Indian/Alaska Native peers.
While 47 percent of Asian students and 32 percent of white students scored at or above proficient in math, just 7 percent of black students and 12 percent of Hispanic students did the same.
There were no changes in the black-white and white-Hispanic score gaps for math or reading between 2013 and 2015. In fact, none of the racial and ethnic subgroups performed significantly differently than they had in 2013.
Girls continue to outperform boys in reading, and boys continue to outperform girls in math.
In a bright spot, the average math scores for English-language learners went up by 6 points over two years. Carr explained that this was primarily due to an increase in the number of Asian students identified as English-learners. "We weren't surprised once we got a good sense of those demographics," she said.
The 2015 NAEP results for 4th and 8th grade students , released in October, showed math scores had declined for those grades as well. Reading scores were steady for 4th graders but declined for 8th graders since 2013.
On seeing those scores, advocates placed blame in a variety of placesthe Common Core State Standards, frequent testing, the economy, and demographic changes were among the targets.
Those contentions are likely to resurface with the 12th grade scores. However, it's important to note that NAEP scores cannot point to causation, and that education researchers say such explanations should be viewed with skepticism.
When asked whether high school seniors take the test seriously, Carr said motivation isn't much of a concern. The number of answers students omitted and other data, she said, showed that "students are not interacting with this assessment any differently than they have in the past."
Students can choose to opt out of the test, though, and this year participation rates did drop a bit, she said. "But it was nothing that concerned us [or made] us think that the students we have in the sample today are any different from what we had in the sample in previous years."
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