Readability, which is the ease in which text can be read and understood, is an important measure that is used to pair text with a child’s reading ability. For kids to develop strong reading skills, they need to choose texts that are within their reading ability.
Choosing a good book for a young reader is similar to choosing a good shoe, it must “fit.” You wouldn’t buy a size 9 pair of shoes for your child if they wear size 7. The same goes for books! Kids must read books that match their reading level.
There have been several readability formulas developed by literacy researchers over the years. A few widely used formulas include the Flesch-Kincaid Grade Level test, ATOS (developed by Renaissance Learning) and Lexile (developed by MetaMetrics). When we launched Pocket Tales, we decided to use one of these measures because we felt teachers would be familiar with how they worked, but it wasn’t an easy decision.
We chose ATOS over the others. Here are the 4 reasons why:
1. Widely used (and accepted) by our teachers
A significant majority of the teachers that currently use Pocket Tales use it in combination with Accelerated Reader, Renaissance Learning’s assessment software. By choosing a readability formula our teachers and students were already familiar with, we felt our reading game would be easier to integrate into these classrooms.
2. Easy to understand
ATOS is a fairly straightforward measure to understand. A book with an ATOS reading level of 3.4 means that book’s text complexity is in line with an average reader in the 3rd grade and 4th month of schooling. It’s easy for a teacher to quickly discern whether a child is reading below, at or above the average reading level of other kids at the same level of schooling using this approach.
With Lexile, the measures are based on a 2,000 point scale. An average 2nd grade level reader would have a Lexile range of 390L to 690L. If that 2nd grader does not know what their Lexile measure is, it may be difficult for them to interpret or relate to what these numbers mean.
Where things get complicated is pairing text complexity with content appropriateness. While a 3rd grade student may be reading at a text complexity level of 8 (i.e. 8th grade), that doesn’t necessarily mean that they should be reading the content of a level 8 book. Lexile attempts to provide this additional context with Lexile ranges, or a range of books that are appropriate in complexity as well as content maturity for that reader.
Pocket Tales is creating a formula and framework similar in nature to the Lexile range to support this for ATOS within our reading game. Our formula gives the reader an ATOS level score, and based on this score, recommends books within an appropriate complexity and content level range based on their ATOS score.
3. ATOS uses more factors to evaluate text complexity than Lexile
ATOS takes more factors into account than Lexile to determine text complexity.
Factors in ATOS measure are:
Average Sentence Length + Average Word Length + Vocabulary Grade Level + The Number of Words in a Book
Factors in Lexile measure are:
Sentence Length + Word Frequency
We felt because ATOS takes more factors into account, it provides a more accurate gauge of complexity than Lexile.
4. Open and free
ATOS has made its readability measures data free and open to anyone to access it. It also allows anyone to submit their text to have it analyzed and scored without any cost, while Lexile charges to have some pieces of text analyzed. We felt that an open, free approach would invite more publishers to submit their texts to be analyzed and scored by ATOS in the long-term, which in turn would yield a higher number of books with ATOS readability scores.
We’re big fans of open and free systems when it comes to education.
There are tens of thousands of books that have already been analyzed and given an ATOS score. This was important for us as it gave us a large database of books with scores to work with immediately.
Bonus Consideration: CCSS valid measure of text complexity
It is nearly impossible to build an educational application without tying learning outcomes to Common Core State Standards (CCSS). It was extremely important for us to choose a readability formula that was endorsed and accepted by CCSS. The Common Core has named both ATOS and Lexile as valid measures of text complexity.
Readability is at the heart of everything we do at Pocket Tales. Our goal is to help kids discover great books that are appropriate in content and complexity for young readers. As we move forward, we will constantly evaluate book readability formulas and measures used inside our reading game.
What do you think? We’d love to hear your thoughts in the comments!