Meaning of Lexiles

See the following site
(http://www.lexile.com/about-lexile/lexile-overview/)


A book, article or piece of text gets a Lexile text measure when it's analyzed by MetaMetrics. For example, the first "Harry Potter" book measures 880L, so it's called an 880 Lexile book. A Lexile text measure is based on the semantic and syntactic elements of a text. Many other factors affect the relationship between a reader and a book, including its content, the age and interests of the reader, and the design of the actual book. The Lexile text measure is a good starting point in the book-selection process, with these other factors then being considered. Lexile text measures are rounded to the nearest 10L. Text measures reported below 0L are reported as BR for Beginning Reader.

Grade
Reader Measures, Mid-Year
25th percentile to 75th percentile (IQR)
1
Up to 300L
2
140L to 500L
3
330L to 700L
4
445L to 810L
5
565L to 910L
6
665L to 1000L
7
735L to 1065L
8
805L to 1100L
9
855L to 1165L
10
905L to 1195L
11 and 12
940L to 1210L

Figure 1. Typical Reader and Text Measures by Grade

Notice that there is considerable overlap between the grades. This is typical of student reading levels and texts published for each grade. In addition, the level of support provided during reading and reader motivation have an impact on the reading experience. Students who are interested in reading about a specific topic (and are therefore motivated) often are able to read text at a higher level than would be predicted by the reader’s Lexile measure.

Although a student may be an excellent reader, it is incorrect to assume that he or she will comprehend text typically found at (and intended for) a higher grade level. A high Lexile measure for a student in one grade indicates that the student can read grade-level-appropriate materials at a very high comprehension rate. The student may not have the background knowledge or maturity to understand material written for an older audience. It is always necessary to preview materials prior to selecting them for a student.

It is important to note that the Lexile measure of a book refers to its text difficulty only. A Lexile measure does not address the content or quality of the book. Lexile measures are based on two well-established predictors of how difficult a text is to comprehend: word frequency and sentence length. Many other factors affect the relationship between a reader and a book, including its content, the age and interests of the reader, and the design of the actual book. The Lexile measure is a good starting point in your book-selection process, but you should always consider these other factors when making a decision about which book to choose.

The real power of The Lexile Framework is in matching readers to text—no matter where the reader is in the development of his or her reading skills—and in examining reader growth. When teachers know Lexile reader measures and Lexile text measures, they can match their students with the texts that will maximize learning an

Above information is taken from the Lexile Site: http://www.lexile.com/about-lexile/lexile-overview/