The screw-up provided new ammunition to opponents of so-called “high-stakes” testing, which has become increasingly popular around the country. “This is a dramatic example of why high-stakes decisions about students should not be made on the basis of a single test,” says Michael Feuer, director of the National Research Council’s Board of Testing and Assessment. The real problem, Feuer says, is that testing is an inexact science. Other major testing companies have admitted scoring errors this year. And testing foes say that even accurate scores don’t tell the whole story. In any case, New York is rethinking the value of standardized exams. Two weeks ago, school officials voted to base future promotions on attendance and class work as well as test scores. Maybe they’ve learned a lesson.