CAMBRIDGE, Mass. - IN March, Les Perelman attended a national college writing conference and sat in on a panel on the new SAT writing test. Dr. Perelman is one of the directors of undergraduate writing at Massachusetts Institute of Technology. He did doctoral work on testing and develops writing assessments for entering M.I.T. freshmen. He fears that the new 25-minute SAT essay test that started in March -- and will be given for the second time on Saturday -- is actually teaching high school students terrible writing habits.

"It appeared to me that regardless of what a student wrote, the longer the essay, the higher the score," Dr. Perelman said. A man on the panel from the College Board disagreed. "He told me I was jumping to conclusions," Dr. Perelman said. "Because M.I.T. is a place where everything is backed by data, I went to my hotel room, counted the words in those essays and put them in an Excel spreadsheet on my laptop."

In the next weeks, Dr. Perelman studied every graded sample SAT essay that the College Board made public. He looked at the 15 samples in the ScoreWrite book that the College Board distributed to high schools nationwide to prepare students for the new writing section. He reviewed the 23 graded essays on the College Board Web site meant as a guide for students and the 16 writing "anchor" samples the College Board used to train graders to properly mark essays.

He was stunned by how complete the correlation was between length and score. "I have never found a quantifiable predictor in 25 years of grading that was anywhere near as strong as this one," he said. "If you just graded them based on length without ever reading them, you'd be right over 90 percent of the time." The shortest essays, typically 100 words, got the lowest grade of one. The longest, about 400 words, got the top grade of six. In between, there was virtually a direct match between length and grade.