In Valerie Strauss’s blog “The Answer Sheet” in the “Washington Post,” Professor Alyssa Hadley Dunn subjected Campbell Brown’s statements on the Stephen Colbert show to a fact check. Dunn, who taught high school English, is now an assistant professor of Teacher Education at Michigan State University.

Dunn compares what Brown says to what research shows.

She concludes: “Quite simply: there is no research demonstrating causation between teacher tenure laws and lower rates of student achievement, which is the entire argument behind the lawsuit.”