School districts trying to administer Indiana's required standardized test encountered new problems Tuesday that forced the state to suspend testing for a second straight day.

Superintendent of Public Instruction Glenda Ritz ordered testing halted after schools across the state reported issues accessing the online portion of the ISTEP+ exam. The directive came a day after 27,000 students struggled to connect and complete the test.

Ritz said the issues were "unacceptable" and pledged that the Department of Education would work with schools to ensure they have enough time to administer the test once the problems are corrected.

"All of our students deserve to take a test that is valid, accurate and reliable," she said in a statement.

Lisa Cutshall, technology director for Madison Consolidated Schools, said the day started out smoothly with nearly 1,000 students finishing the online portion of the test. Cutshall said problems started to spike around 11 a.m.

"We were told that they were going to fix things (Monday night). I got my hopes up (Tuesday morning) when things were moving so well," Cutshall said.

Cutshall estimated that only 25 percent of Madison students have been able to complete their ISTEP+ testing.

"Most students have completed at least one session of the test, but we probably still have quite few students with the bulk of test to accomplish."

This is the third straight year that students in grades three through eight taking the online portion of the exam have encountered problems, The Indianapolis Star reported.

In 2011, up to 10,000 students statewide were logged off and some were unable to log back in for up to an hour while taking the test. The state invalidated 215 scores that year because they were lower than expected.

About 9,000 students were kicked offline during the test last year.

Vendor CBT/McGraw-Hill LLC had initially reported all testing systems were running fine Tuesday. But it changed its status as students began logging in and connection problems arose, urging schools to suspend testing until 12:30 p.m.

Southwestern Middle School Principal Trevor Jones said when the test shuts down, school teachers and administrators try to get students back to as normal a schedule as possible.

Jones called the situation disruptive, saying it wasn't fair to students who are trying to take the test, or teachers who are trying to administer it.

"It's just a bad situation. If a kid has test anxiety, for instance, it prolongs that anxiety. There's nothing fair about being in the middle of a test and then having to wait 20 minutes to get back on."

Jones said the test results could "absolutely not" be accurate because of the disruptions.

"It's just human nature. If I'm taking a test and having technical problems, it's going to change my thought process to the test. I may speed up while it's working, just to try to get finished with it while I can."

Jones added that if a paper and pencil test had similar disruptions, the test scores would be invalidated.

Carol Stream, Ill.-based McGraw-Hill administers the exam under a four-year, $95 million contract with the Indiana Department of Education. The contract runs through June 2014.

The contract requires McGraw-Hill to provide "uninterrupted" computer availability every school day from 7 a.m. to 6 p.m. for the two weeks prior to each testing window, as well as for the entire testing window.