How is Text Complexity Determined?The complexity of text is determined using the Lexile Analyzer, a software program that evaluates the reading demand—or readability—of books, articles and other materials. The Lexile Analyzer produces a ranking by measuring the complexity of the text by breaking down the entire piece and studying the following criteria:

sentence length grammar word frequency length of text

Ranges of Lexile rankings are correlated with expected grade levels. Generally, longer sentences and words of lower frequency lead to higher Lexile measures; shorter sentences and words of higher frequency lead to lower Lexile measures.

In general, Lexile ranking scores fit into grade levels in the following pattern:

Grade Level Lexile Levels

K

1

200-299

2300-399

400-499

3500-599

600-699

4 700-799

5 800-899

6 900-999

7 & 8 1000-1100

Grade Text Demand Study 20091 230L to 420L2 450L to 570L3 600L to 730L4 640L to780L5 730L to 850L6 860L to 920L7 880L to 960L8 900L to 1010L9 960L to 1110L10 920L to 1120L

11 and 12

1070L to 1220L

Reading Programs:Reading programs, generally, use texts that fit within a grade’s Lexile ranking range, and then ensure that other book design elements for that level are consistent. These elements include:

Text Presentations (e.g. layout, location of text, size of lettering)

Illustrations (amount of illustrations vs. text)

Length of Text (total length, # of words per sentence, # of lines per page, # of pages with text in a book)

Content