State Senator Larry Pogemiller plans a hearing today to find out what caused the scoring errors on Minnesota's Basic Standards Tests. Almost eight thousand students were told they failed the math portion of the test when in fact they passed. Over three hundred of those students may have been barred from graduating due to the error by National Computer Systems, the company that grades the tests. This isn't the first time a testing company has made a mistake. In 1997, Kentucky found that a different testing company had underscored tests used to give schools performance ratings. Lisa Gross of the Kentucky Department of Education talks with MPR News.