This year’s national average scores for the SAT plummeted seven percentage points from last year’s average. The drop — the largest in 31 years — follows this year’s introduction of a new version of the SAT, which included a writing component.

The plunge was caused mainly by the fact that fewer students than in past years took the test multiple times, College Board spokeswoman Caren Scoropanos said. Scoropanos said she does not believe the revised structure of the test caused the average scores to decrease.

“The major reason for the fluctuation is that students re-tested in smaller numbers, meaning that less students took the test a second time,” she said. “Usually, when students take the test for a second time, their scores go up by an average of 30 points.”

Opponents of the SAT said the data confirmed that the SAT is not a reliable predictor of a student’s capacity for collegiate success.

“We think [the dip] demonstrates the fundamental lack of value of the SAT as an accurate measure of preparedness for college,” said Robert Schaeffer, a spokesman at the National Center for Fair and Open Testing. “It is demonstrated by the fact that a small change in the test design and test takers’ behavior — fewer students taking the test — can cause the largest score change in three decades.”

Schaeffer said he believes that more schools may stop requiring SAT scores after these recent developments.

Yale Dean of Admissions Jeff Brenzel said he did not believe he had enough information to speculate about the cause of the decline.

The median SAT verbal score for Yale’s class of 2010 is 750 and the class’s median SAT math score is 740, the same as for Yale’s class of 2009.