Factors used in determining the Guided Reading Level of a book
The Fountas and Pinnell system of leveling books for developing readers is based on several text characteristics. These make up the criteria we use for leveling the books on our website.
Genre is one characteristic we consider when leveling a book, as well as content or subject matter. Structure – the way a text is organized or presented – is another important factor when leveling. Fiction and nonfiction texts are organized quite differently, and this plays an important role in determining the reading level of a book. Themes are another factor –  the level of complexity or the number of themes within a story – that are used to level texts. 
Sentence length and complexity  are considered, as is vocabulary, specifically how familiar it is to readers. We also analyze the difficulty of the words the reader must recognize or decode when reading the text. Use of a lot of high frequency words or repetition of key words in the text will make a text more accessible.
The use of illustrations and graphics in either fiction or nonfiction texts influences the reading level. There is increasing variability in the way drawings, illustrations, and graphics are used in children’s books, and these have an impact on how children read.
Finally, book and print features are the physical aspects of a book – length, size, and layout of a text. The tools that are included in a book, such as the table of contents, glossary, or indexes are also considered when leveling.
This gives you a brief idea of our method of leveling books for developing readers. For a chart comparing Guided Reading levels to other leveling systems Click Here.
