Reading LevelsMCAS uses multiple programs to determine a student's instructional reading level. Read180 and SRI provide students with a Lexile: STAReader and AR use ATOS. ATOS and Lexiles use different mathematical formulas to determine text readability.
Readability formulas provide an estimate of a book's difficulty based on selected variables in the text, but DO NOT analyze the suitability of the content or the literary merit for individual readers. The school librarian and classroom teacher can assist the student in selecting a book that is just right.
- ATOS - uses the number of characters in a word, the number of words in a sentence, the average grade level of the words in the book and the full text of the book. Renaissance Place also identifies books appropriate for lower grades (LG) middle grades (MG) and upper grades (UG).
- Lexiles - uses word frequency and sentence length within 100 word passages to determine text readability. Lexilies do not identify books appropriate to student grade level.
A readability index is a good starting point for book-selection process. Other factors also affect the relationship between a reader and a book including content, the age and interests of the reader and the design of the actual book. Students who are interested in reading about a specific topic, therefore motivated, are able to read text at a higher level than would be predicted by a readability index.
Grade Levels, Lexiles* and AR
Text Measures AR AR ZPD** 1 Up - 300L 200L - 400L LG 1.0 - 2.5 2 140L - 500L 300L - 500L LG 1.0 - 2.5 3 330L - 700L 500L - 700L LG 2.6 - 3.6 4 445L - 810L 650L - 850L LG 3.0 - 5.0 5 565L - 910L 750L - 950L LG 3.4 - 5.4 6 665L - 1000L 850L - 1050L MG 4.0 - 6.5 7 735L - 1065L 950L - 1075L MG 4.3 - 7.5 8 805L - 1100L 1000L - 1100L MG 4.5 - 9.0 9 855L - 1165L 1050L - 1150L UG 4.6 - 9.0 10 905L - 1195L 1100L - 1200L UG 4.7 - 10.0 11 and 12 940L - 1210L 1100L - 1300L UG 4.8 - 12.00
* Some text have a non-standard format and cannot accurately show a Lexlie. Those texts include: Adult Directed, Non-Conforming, High-Low, Illustrated Guide, Graphic Novel, Beginning Reading and Non-Prose. More information can be found at Lexlie Codes.
** ZPD (Zone of proximal development) is the optimal range where learning takes place. It is a concept developed by the psychologist Lev Vygotsky.Resources