Sometimes a Lexile measure by itself is not enough information to choose a particular book for a particular reader. This is why some books get Lexile codes—two-letter designations that appear before the Lexile measure (for example, AD580L).
The Lexile code gives you more information about a book that relates to its developmental appropriateness, reading difficulty, and common or intended usage. Word frequency and sentence length—the two text characteristics that determine a Lexile measure—do not describe all of the content of a book. Lexile codes provide some context to the numerical measure to further help you guide readers toward fruitful reading experiences. There are also Spanish Lexile codes for Spanish titles with Lexile measures.
AD: Adult Directed
Picture books are frequently considered for an AD or "adult directed" code because they are usually read to a child, rather than a child reading them independently. This is the classic example of parent and child sitting together on the couch with the book open in their laps. Although seemingly easy reading, picture books can still present a challenging independent reading experience to an age-appropriate reader for reasons of text difficulty and book layout or design.
The text difficulty of picture books varies widely across the genre. For instance, Maurice Sendak's Where the Wild Things Are (HarperCollins Publishers) is a beloved read-aloud for preschoolers. Its Lexile measure of 740L, however, is around the average reading ability for someone ending fourth grade. Upon a closer look, the text comprises long sentences and contains some fairly high-level vocabulary such as "mischief," "private," "gnash," and "rumpus." The parent on the couch would help the preschooler sound these words out and decipher these long sentences. Therefore the book is coded adult directed and the measure is AD740L.
Additionally, picture books can have design elements that may visually complicate reading for a child. Factors such as font size, typeface, page layout, legibility, and the relationship between pictures and text may significantly impact reading comprehension. The story and illustrations in Where the Wild Things Are are perfect for young children. But the lines of the text are close together and the sentences are spread over multiple pages, often in long horizontal lines. These design elements may challenge a child's ability to read the book independently even if the text difficulty is well matched. Initially, a more advanced reader may need to read the book with a child.
The NC code is applied to books that have a Lexile measure markedly higher than is typical for the publisher's intended audience or designated developmental level of the book. The Lexile measure of a book is compared to the Lexile range of readers in the intended audience in order to make an NC code determination.
The NC code is useful when matching high-ability readers with a book that's still at an appropriate developmental level. Alternatively, some picture books with disproportionately high Lexile measures may receive an AD (Adult Directed) code.
Seymour Simon's Amazing Aircraft (SeaStar Books) is coded NC710L. Its spine reads "grades 1-3" but its Lexile measure is higher than a typical early elementary school student's ability range. Therefore the book is coded as Non-Conforming.
A text designated as "HL" has a Lexile measure much lower than the average reading ability of the intended age range of its readers. Librarians and booksellers sometimes refer to young adult books with disproportionately low Lexile measures as "high-low" books, meaning "high-interest" plus "low-readability." These books receive an HL code. Often fiction, HL books are useful when matching older (grade 7 and beyond) struggling or reluctant readers with text at both an appropriate difficulty level and an appropriate developmental level.
Despite their short sentences and basic vocabulary, HL books are designed to appeal to readers at a more mature developmental level. For example, Beth Goobie's Sticks and Stones (Orca Soundings) is classified as a young adult book and measures 430L—an average reading ability for 2nd graders. The book's characters are high-school students who struggle with the many challenges that face high-school students such as dating and gossip. Therefore, the book is coded HL430L.
IG: Illustrated Guide
The IG code is applied to books that consist of independent pieces or sections of text such as in an encyclopedia or glossary. These text pieces could be moved around without affecting the overall linear flow of the book. Usually nonfiction, IG books are often used as a reference resource rather than read in their entirety like a storybook. Their distinguishing text characteristics include:
- technical vocabulary, definitions, and pronunciation guides in parentheses or contrasting type
- integration of illustrations and diagrams into the text
- pull-quotes, factoids, and other categorical marginalia
- the presentation of each discrete topic on one to two pages
These text characteristics do not necessarily impact reading comprehension or developmental appropriateness. Instead, the IG code conveys an idea of the kind of book and what the book typically will be used for in the classroom or library.
Birds of Prey by Dr. Gerald Legg (Franklin Watts Library) is coded IG. Separate paragraphs are arranged upon the page, functioning more like multiple-sentence captions. A particular reading order is neither indicated by the layout nor important to comprehension. Thus the book measure is IG320L.
GN: Graphic Novel
The GN code indicates that the book is a graphic novel or comic book. The text of GN books appears primarily in voice or thought bubbles integrated into comic book-style illustrations. Graphic novels tend to contain a larger percentage of dialogue than most other genres of books. They also typically lack some of the required text conventions of dialogue, such as putting "she said" after a quoted sentence, because illustration methods are used to indicate spoken text. The impact of picture support on reading comprehension is not captured in the Lexile measure of a graphic novel. To Dance: A Ballerina's Graphic Novel (Aladdin) , written by Siena Cherson Siegel and illustrated by Mark Siegel, is coded as GN610L.
Also see this article from Edutopia about the instructional value of using graphic novels and comics in the classroom.
BR: Beginning Reading
A text that receives a Lexile measure of 0L or below is coded BR. The Lexile measure is shown only as BR, without the zero or negative number appearing. These books are appropriate for the emergent reader. Often BR books are not used for independent reading, but are read aloud by an adult to or with the child.
Hop on Pop by Dr. Seuss (Random House) is a BR book.
The NP code is for any book comprising more than 50% non-standard or non-conforming prose. NP books do not receive a Lexile measure, merely the NP code. Some common examples of non-prose content are poems, plays, songs, recipes, and text with non-standard or absent punctuation. Since the Lexile Framework is based on prose analysis, Maurice Sendak's Alligators All Around (HarperTrophy) is coded NP. The text of the book is not in complete sentences and lacks punctuation entirely. The text difficulty of such a book cannot currently be assigned a Lexile measure.