The Minnesota Department of Education suspended online testing Wednesday for the second time this spring in the wake of another cyberattack that hobbled the vendor’s computer system and prevented students across the state from completing standardized science exams.

The computer problems, which have repeatedly plagued test takers this year, also spurred a blistering response from frustrated lawmakers, teachers and state education officials. Minnesota Education Commissioner Brenda Cassellius questioned whether Pearson, the state’s testing vendor, has done enough to safeguard its system.

“It is simply unacceptable and unfair to subject students and teachers to this kind of uncertainty in a high-stakes testing environment,” Cassellius said.

The commissioner said that after its last suspension April 21, the company told state leaders it added new security measures to prevent future disruptions. “Given the need to suspend testing today, I have questions about Pearson’s ability to follow through on their assurances,” she said.

Department officials suspended testing around lunchtime Wednesday and hours later informed school districts that testing would not resume on Thursday. 

About 44,000 Minnesota students from around the state still need to take the science exam by Tuesday’s deadline, but education officials were unsure how many students were affected by Wednesday’s disruption.

Students who attempted to take the Minnesota Comprehensive Assessments (MCA) science exam Wednesday had difficulty logging on or were thwarted by Pearson’s sluggish system. 

Pearson officials described the attack Wednesday as larger and more sophisticated assault on its system than the one that occurred April 21, which prompted the state to suspend testing for about a day. Company officials said they are working to strengthen the system.

“[These] attacks are not attempts to access student data, and at no time was student data compromised,” company officials said in a statement. “We understand this caused difficulties today for learners and we apologize for any inconvenience.”

Charlene Briner, the department’s chief of staff, said that in addition to suspending testing, the state will hire an outside company to investigate whether the disruptions have affected student test scores. The department is also considering legal recourse, she said.

“It’s so completely unacceptable,” she said. “It’s bad enough when kids have one or two disruptions. But for this to happen multiple times?”

The testing trouble comes as state legislators are debating whether current testing requirements are too burdensome and a growing number of metro-area parents are having their children opt out of MCA testing.

The state Senate is weighing a proposal that would limit the number of hours students can spend on standardized tests and allow school districts to set aside test results that are used in school ratings and teacher evaluations. 

“It’s absolutely unacceptable that NCS Pearson Inc.’s system has failed hundreds of thousands of our hardworking K-12 students,” said state Sen. Chuck Wiger, DFL-Maplewood, the proposal’s author.

Education Minnesota, the statewide teachers union, is supporting the Senate proposal and has also launched a petition calling on Pearson to refund the state $12.5 million due to the disruptions.

“The MCA tests have been nothing but trouble this year,” said Denise Specht, the group’s president. “Hundreds of educators have reported problems with the 2015 MCAs. It’s just day after day after day of glitches, delays and frustration.”

Teachers say test season is normally a stressful time for both educators and students. When testing is disrupted, that anxiety is even greater.

“To me, this just isn’t working for students,” said Elizabeth Lane, a teacher at Twin Oaks Middle School in the Prior Lake-Savage Area school district. “From a teacher’s perspective, and what parents want, is for students to be successful. And how can they be successful when they’re anxious and stressed?”

Two years ago, the state’s relationship with its previous testing vendor, American Institutes for Research (AIR), soured when an estimated 15,000 students from 400 schools encountered issues logging on to take the MCAs — or had their sessions timed out early. A consultant hired by the state later determined that the disruptions did not affect student scores.

AIR did not seek to renew its contract and testing giant Pearson was awarded a three-year, $33 million contract.

With Pearson as the new vendor, students began taking the MCAs exclusively online this year. In previous years, the tests were given both on computers and paper.

Cassellius has recently testified at the Capitol that while online tests offer faster and better results, the technology that supports those tests might be too new to support seamless administration.