A leading education firm is acknowledging that it messed up when evaluating alternative assessments for thousands of students with disabilities.

Pearson said this week that there were errors affecting more than 4,400 students who were part of the Virginia Alternate Assessment Program, which offers alternative assessments for students with significant cognitive disabilities, the company said.

Unlike traditional testing, the alternative assessments are designed to measure student progress by evaluating a portfolio of work completed over the course of the year.

While the students’ tests were scored accurately, the company said there were mistakes made in converting the scores to reflect a level of achievement: pass/proficient, pass/advanced or fail.

“We sincerely apologize to the students, parents, schools and school divisions as well as to our colleagues at the Virginia Department of Education,” Pearson said in a statement. “We understand the importance of accurate reporting and know that the school divisions are now working very hard to make internal adjustments to their scores before reporting them to parents and the state.”

However, the error was not caught before some parents were provided incorrect results, The Washington Post reports. Many parents were told this summer that their children passed the test when they actually had not.

A spokesman for the state Department of Education told the newspaper that the situation is “truly regrettable.”

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