The progress of many struggling readers is undermined by slavish adherence to Lexile reading-level scores. Though I haven’t observed that a majority of teachers, learning consultants, and school psychologists are subservient to these scores, I’ve observed it far too often to think it’s rare.

In contrast, it’s obvious that Lexile scores, flexibly used as tentative guides, can advance decision-making but cannot take the place of a highly knowledgeable and insightful teacher’s observations.

Essentially, Lexile scores are produced by readability formulas that analyze the difficulty of texts, such as passages, articles, and books. To do this, they analyze the length of sentences and the frequency with which words occur.

They consider longer sentences with rarer words, words like "perspicacious" and "transmogrification," more difficult to understand than shorter sentences full of commonly used words like "maybe" and "first."

The Limitations of Lexile Scores

Lexile scores can be helpful. They can help librarians and teachers get a rough idea about the difficulty of materials for hypothetical groups of struggling readers. But they cannot tell teachers or parents if a specific article or book is appropriate for a specific child, especially a struggling reader.

The reason is simple: Lexile scores are lifeless. They don’t know the struggling reader. They don’t know Marylee’s likes and dislikes, her background, her oral language abilities, her anxiety levels, her independent work habits, her energy level, and so on.

From authoritative literature, here are some typical warnings about Lexile scores:

Professors Walpole and McKenna concluded that: "Estimating readability is not an exact process. Lexile ... reading levels are merely guidelines for making good choices. Unfortunately, they give us the impression of being more precise than they actually are. Moreover, they do not account for the needs of a particular small group."

Professor Ardoin and his colleagues found that: "…none of the readability estimates [including Lexile scores] were significantly related to [the number of words read correctly per minute] … These findings replicate and extend previous research suggesting that estimates of passage difficulty based on readability estimates are not related to students’ oral reading performance, and students’ readings of passages are a better gauge of passage difficulty than are readability estimates."

Professor Emeritus Stephen Krashen concluded that Lexile scores can potentially prevent struggling readers from reading materials they’re motivated to read: "A narrow application of the Lexile Framework will needlessly limit readers' choices, keeping readers in a narrow range of texts… While children may select easy books for free reading, they often select books that are considered too hard…. [But] these ‘hard’ texts might be very meaningful for readers with special interests and who are willing (and eager) to focus on the parts that are relevant to them."

The Bottom Line for Lexile Scores

Consider a struggling reader’s Lexile score as a single piece of information, a small part of a jigsaw puzzle that can help identify appropriate reading materials for her but not by itself.

Don’t completely accept a statement that your child’s Lexile score shows she should read books at Lexile level 451 (roughly mid-second grade). Blindly accepting a Lexile score as “all-telling” is akin to believing that every 6'7” ninth-grader, regardless of athleticism, will become a college basketball star.

So, what if you and your child’s teachers believe her Lexile score is the proper reading level for everything she reads and that it gives her teachers all the information they need to instruct her? Your child’s reading struggles may intensify. Here are three reasons.

1. Her Lexile level may be too difficult. It may frustrate her while unwittingly teaching her that she’s a “failure.” She’s not. She’s reacting to a terrible prescription.

2. Or she may find that the Lexile level materials she’s reading are so easy and infantile that she’s bored and thinks, “That proves it. My teachers, my parents, everyone knows I’m dumb.”

3. Or she may face a "helpfully intended" barrier. She, for example, may desperately want to read a book that all her friends are raving about, but she’s not allowed. It has too high a Lexical level. Her school has a strict policy: Nothing above or below your Lexile level.

A Response to Rigidity

If your child is making minimal progress in reading and her reading materials rigidly adhere to her Lexile score, no matter what, I strongly suggest that you formally request pertinent reading and writing information that sheds light on her interests, likes and dislikes, and current reading and writing abilities.

This includes her independent, instructional, and frustration levels on a well-respected informal reading inventory, such as the Qualitative Reading Inventory; oral samples of her reading books at, above, and below her Lexile level; and the interest she has and enjoyment she gets from reading personally interesting materials at different levels of difficulty.

The Take-Home Point

Like one piece of a 100-piece jigsaw puzzle, Lexile reading-level scores can prove helpful but limited. The problem is not the score itself, but why and how it’s used. Like all rigidity, a narrow and rigid adherence to Lexile scores can intensify a student’s struggles with reading. Don’t let this happen.