http://teacher.scholastic.com/products/sri_reading_assessment/programoverview.htm

SCHOLASTIC READING INVENTORY™ (SRI)
is a research-based, computer-adaptive reading assessment program for students in Grades K–12 that measures reading comprehension on the Lexile Framework® for Reading. The most powerful feature of the SRI is its ability to administer fast and reliable low-stakes assessment to inform instruction and make accurate placement recommendations. Aligned to state tests, SRI helps educators forecast student achievement to those important goals.