Some Minnesota school leaders are questioning the validity of recent online tests in the wake of technology problems that have plagued students with interruptions and delays over the past two weeks.

Those concerns came on the heels of the state Department of Education's decision Wednesday to give students more time to complete online versions of the Minnesota Comprehensive Assessments, tests taken in the classroom that hold high stakes for students, teachers and schools. Students had been expected to complete the math and reading tests by May 10 and science tests by May 17. No new deadlines were set.

"None of the decisions around testing are made lightly," Education Commissioner Brenda Cassellius said in a prepared statement. She acknowledged that some educators have suggested that this year's tests be suspended altogether because of the technology glitches.

While pleased by the testing period extension, some school officials said they suspect technology problems have affected students' performance.

The situation "is incredibly frustrating for our students," said Minnetonka Superintendent Dennis Peterson. "I believe it has the potential to lower test scores."

That concern was echoed in the Burnsville-Eagan-Savage district, where students taking the online math test have encountered problems. "How can students do their best effort when the test environment isn't working?"asked Superintendent Randy Clegg.

In Duluth, students have had problems throughout the online testing period. Officials there are still assessing their extent and the effect they may have had on test scores. "High-stakes tests produce a lot of stress to begin with," said Tawnyea Lake, Duluth Public Schools' director of assessment and evaluation. "When you throw in these kinds of problems, you're making it much worse for students and teachers. We can't help but wonder what kind of impact it's going to have."

More than half of Minnesota students have completed the MCAs, but as of Tuesday, about 312,000 tests still needed to be completed, said Education Department spokeswoman Charlene Briner.

After the testing window closes — whenever that might be — department officials plan to analyze test results to see if student performance was hurt, she said. "We really are monitoring daily; we don't know what the next days will bring," Briner said.

The MCAs influence the state's current school rating system, which requires chronically underperforming schools to make improvements. Test scores also factor into Q Comp, Minnesota's merit pay system for teachers, and federal poverty aid for schools.

Minnesota had no significant issues with online MCAs last year. This year, more schools opted for online instead of paper tests. All science tests are taken online and about 95 percent of students are taking math tests online. Of reading test-takers, about 30 percent of students are completing them online.

But with more technology use have come more technology problems.

On April 16, the state temporarily suspended testing after computer server issues kept some of about 5,000 students taking the online math test from logging on or forced them to end their sessions early. Testing resumed the next day.

Jon Cohen, executive vice president of American Institutes for Research (AIR), the department's testing vendor, said then that system engineers were able to identify the cause of the slowdown and expected no more problems.

But on April 23, 48 school districts reported similar problems to the state. The following day, half a dozen districts reported technology issues related to coding problems that affected about 60 students, Briner said, which AIR resolved.

Cohen said Wednesday that the company only found evidence that its server had problems April 16. He said testing has gone "swimmingly" since then.

He disputed assertions that test results might be rendered invalid, saying online tests are designed for students to pause and restart under scenarios such as disruptions to school servers or machine malfunctions. What to do in those situations is outlined in the state's testing manual, he said.

"This is something that didn't blindside anyone," Cohen said.

On Wednesday, Briner said the state asked AIR, which has a three-year contract with the state ending in 2014, to ramp up its resources to help school districts prevent and address technology problems.

Problems are surfacing in other states, as well. On Wednesday, Indiana reopened testing after suspending online tests Tuesday because of interruptions in its system, run by CTB McGraw-Hill. Oklahoma schools have had similar issues with that company..

On Wednesday, the U.S. Department of Education released a statement supporting Minnesota's decision to extend the deadlines. 612-673-4469 612-673-4141 • Twitter: @kellystrib