Twelve percent of Chicago Public School teachers 1,927 teachers in charge of over 55,000 students are not up to par, according to the standards of the No Child Left Behind Act. Although letters went out to parents this week, both public school officials and teachers union representatives said that it was not time to panic, since teachers have until 2006 to upgrade their credentials. Furthermore, schools CEO Arne Duncan questions whether the highly qualified teacher label is accurate, noting that at Hawthorne Scholastic Academy, where 56% of teachers don t merit the label, over 90% of students meet national norms in reading and math.