Faced with a tough new reading test this spring, most Minnesota schools saw reading scores plummet and math scores dip slightly on state standardized exams.

Statewide, proficiency in reading dropped from 76 percent to 57 percent, according to Minnesota Comprehensive Assessment scores released Monday. In math, proficiency fell 1 percentage point, to 61 percent. The state's persistent achievement gap between white and minority students showed no real signs of reversing.

But state education officials strongly cautioned against comparing this year's lackluster scores to last year's. That's because this year, students were given a tougher reading test based on standards laid out by a national initiative called Common Core, which seeks to define reading and math skills students should have as they move from grade to grade.

Education Commissioner Brenda Cassellius said the scores do not offer a complete look at what students know. She said historical trends show an upward trajectory and that ACT scores released last week show Minnesota is tops in the nation for the eighth year in a row.

"It's important to look at today's test results for what they are — a snapshot in time that tells us how students are doing in mastering our state standards," she said. "What is needed now is to focus on our efforts and stop moving the goalposts so teachers and students have a consistent target to hit."

Minnesota is in the midst of a testing revolution. There is increasing opposition to high-stakes exams like the MCAs, the results of which factor into federal poverty aid, teacher merit pay and school rankings under the state's accountability system.

This spring, legislators decided to scrap the Graduation Required Assessment for Diploma (GRAD) test, which students had to pass in order to graduate, and to replace it with a suite of tests that measure whether students are ready for college. It was a move supported by Gov. Mark Dayton.

Adding fuel to the testing debate was a spate of computer problems that plagued thousands of Minnesota students taking online MCAs this spring. While some school administrators expected the disruptions to affect results, a department-commissioned investigation determined scores were unaffected.

"We're seeing the limits of using test scores to measure success," said Denise Specht, president of Education Minnesota, the statewide teachers union. "Too many snow days may have lowered scores in some rural districts. Computer glitches affected some students more than others. Snowstorms and modem speeds shouldn't affect how Minnesota measures academic quality, but they do. That's a problem."

But for now, MCAs still matter in Minnesota.

Math gain in Minneapolis

In Minneapolis, officials were cheered by their second districtwide 3-percentage-point gain in math proficiency in a row. This year's increase is a contrast to a 1 percent dip statewide from 2012, when the state allowed districts to give the test up to three times. Minneapolis didn't do that, so it didn't see the same drop as others in 2013, when the test was given once.

"If you go back again and back again, you do better," Minneapolis Superintendent Bernadeia Johnson said.

Forty-three percent of Minneapolis students achieved math proficiency, compared to 61 percent statewide.

Districtwide, students dropped 15 percentage points in reading proficiency, to 42 percent. Although the reading score change isn't comparable to 2012 because of the test change, "it gives us a baseline for future growth," said Eric Moore, the district's research director.

All racial or ethnic groups that Minneapolis tracks showed higher math proficiency, but only American Indian students registered enough gain to slightly narrow the gap with whites; they posted a 4 percentage point gain. In reading, the achievement gap widened, with all groups but Asian students sinking more than white students.

In St. Paul, mixed results

In St. Paul, where efforts to narrow the achievement gap are a priority, white students were 71 percent proficient in both the math and reading tests, exceeding their peers statewide in both categories. White students also saw a 2 percent increase in math results from a year ago.

Despite that gain, only one minority group, Hispanic students, saw a widening of the achievement gap in math, when their results fell by 1 percent from a year ago. Asian-American and American Indian students narrowed their respective gaps by posting 5 percent gains in math proficiency, while black students posted a 2 percent gain, leaving the gap between them and whites unchanged.

Overall, 44 percent of St. Paul students were proficient in math, a 3 percent increase. In reading, 37 percent of St. Paul student were proficient.

"We're very pleased that math results went up — not as much as we would like — but they've gone up, and in some schools, they've gone up in double digits," Superintendent Valeria Silva said in a statement. "But our reading scores indicate that we must now dig deep into the Common Core standards in order to bring up reading results to the levels they should be."

Some poor schools beat odds

For the first time in seven years, students from the Anoka-Hennepin district, the state's largest, scored higher than the state average on all tests at all levels, said district spokeswoman Mary Olson.

The scores ran the socio-economic gamut. For instance, McKinley Elementary School in Ham Lake, with the district's lowest percentage of students using the free and reduced-cost lunch program, scored 73.8 percent in science. Adams Elementary in Coon Rapids, with the district's highest percentage of kids taking free or reduced-cost lunches, scored 70.5 percent — just three points below McKinley.

Among Minnesota schools with the highest level of students living in poverty, Global Academy in Columbia Heights ranked near the top in both reading and math. Charter schools dominated that list, which this year included perennial achievers Harvest Prep/Seed Academy, Hiawatha Leadership Academy and Higher Ground Academy.

"People who like to learn, love to read," said Helen Fisk, director of Global Academy. "People who are curious like to solve problems. We have 400 of the best kids you could ever hope to teach."

'One piece of … the picture'

While the MCAs are an important measuring stick, they don't carry the weight they once did. Under the No Child Left Behind law, math and reading proficiency measured by the MCAs once determined which schools were branded failures and forced to improve. Minnesota was freed from the federal law and rolled out a more nuanced accountability system for schools in 2012. The 2012-13 school rankings based on that new system will be out in October.

In September, National Assessment of Educational Progress scores will be released. That's a test given to fourth- and eighth-graders in every state to gauge math and reading skills at the national level.

"These tests, while important, are just one piece of the overall picture of how students and schools are doing," Cassellius said. "Nothing can replace talking to your child's teacher, reviewing their daily work and visiting your child's school."

Staff writers Steve Brandt, Paul Levy and Anthony Lonetree contributed to this report. kim.mcguire@startribune.com • 612-673-4469 ghowatt@startribune.com • 612-673-7192