The Accelerated Reading levels are based on a formula ( the ATOS) developed by the parent company, Renaissance Learning. The formula uses sentence length along with grade-level vocabulary lists to derive reading levels.
The ATOS formulas use a unique measure of word difficulty compared to other readability formulas: grade-level difficulty of the words. This is computed by looking up the difficulty of the words in a book on a special vocabulary list containing more than 23,000 words developed specifically for ATOS. This new, improved graded vocabulary list reflects temporal change in the vernacular lexicon and incorporates the derivatives of words. Derivatives of words have been typically omitted from such lists in the past, or assumed to function at the same grade level as the root word, either of which might have skewed the outcome. The new list is a synthesis of several sources, including the revised Dale familiar word list (Chall & Dale, 1995), the Educator’s Word Frequency Guide (Zeno, Ivens, Millard, & Duvvuri, 1995), and the Renaissance word frequency corpus. Words from these lists and their derivatives were painstakingly reviewed by vocabulary experts to determine correct grade-level placements, which were then validated through comparisons to words used at various grade levels on major standardized tests.
Now that we've read the technical stuff, what can we take away from all this?
First off, the information about texts becoming easier over time concerns me. We do need a universal leveling system as a tool to ensure that students are adequately prepared for college. Lexile isn't perfect, but if it's widely distributed and well understood by educators and parents, it will certainly
help prepare students for college.
It's important to note that the Lexile levels
use a 75% comprehension rate in their figures (link is to a comprehensive article on Lexiles). This 75% rate assumes a student is reading the text
under the direction of a parent or teacher. A 75% comprehension rate means the text is challenging but not frustrating. New vocabulary is being presented which should be explained by a parent or teacher for maximized learning.
A student's independent reading level would be about 90% comprehension, so subtract 250 Lexiles from your child's Lexile reading level to find a book your child can comprehend
without help, for independent reading time (subtracting 250 gives you a 90% comprehension rate). Adding 250 Lexiles gives you a 50% comprehension rate.
School districts give students reading tests to assign Lexile reading levels. If you homeschool, find a book your child can read to you with 90% accuracy (10 errors per 100 words--don't count dialogue, just prose). Next, look up the Lexile level for that book, and then add 250 Lexiles to that number. The resulting number will be your child's individual reading Lexile. As you're recording/counting your child's reading errors, make sure the errors are truly words your child doesn't know the
meaning of, and not words she just can't
pronounce correctly. Pronunciation of words doesn't correlate with comprehension, most of the time. For example, when you're reading the Bible, does it bother you when you can't pronounce a Hebrew or Greek name? It doesn't lessen your comprehension of the passage, right?
Once you have your child's reading Lexile, help him pick books within -100 Lexiles and +50 Lexiles of the target number. For example, if your child's reading Lexile is 800L, she should read books between 700L and 850L.
I would expect the AR system to break down across the genres of literature because its 23,000-strong, grade-leveled word bank simply can't encompass enough words to adequately cover all genres and time periods. The Lexile system, with its 300-million-strong word bank, would seem to give a more accurate picture of vocabulary difficulty, however, this system would break down when a text contained infrequent words that were nonetheless easy to decode.
Another crucial point is that
leveling systems tell you nothing about the quality of a text.
Quality of writing is most important to me; I now use leveling numbers as
reference only. To adequately prepare for college a student must learn to construct grammatically correct, smooth-flowing, complex sentences. Poor quality literature does
not prepare students for the demands of college-level reading and writing, no matter how high the Lexile or AR level is. Parents and teachers must always open a book and
read it to decide if it's worthy.
Leveling systems are not shortcuts....
just tools.
Lastly, if your child is highly interested in birds, she'll be able to comprehend non-fiction bird text well above her reading level, due to increased motivation. Topics students find uninteresting are harder for them to comprehend, due to lower motivation.
Don't say no very often to material your child is highly interested in, just because the reading level seems too low.
Reading should remain a pleasure. Perhaps you could assign something harder for a prescribed amount of time...say twenty or thirty minutes, and then allow your child to read his favorite material?
Here are some comparisons of the two systems using many Newbery and classic titles. At the bottom of this list is another look at how Lexile levels compare to grade levels.
The Sign of the Beaver
(an AR level of 4.9 refers to 4th grade, 9th month)
AR = 4.9
Lexile = 770
Caddie Woodlawn
AR = 6.0
Lexile = 890
The Adventures of Huckleberry Finn (unabridged)
AR = 6.6
Lexile = 980
Farmer Boy
AR = 5.2
Lexile = 820
The Wheel On The School
AR = 4.7
Lexile = 710
The Cricket in Times Square
AR = 4.9
Lexile = 780
Old Yeller
AR = 5.0
Lexile = 910
The Courage of Sarah Noble
AR = 3.9
Lexile = 610
Little Women
AR = 7.9
Lexile = 1300
The Hobbit
AR = 6.6
Lexile = 1000
Ginger Pye
AR = 6.0
Lexile = 990
The Moffats
AR = 5.2
Lexile = 800
Thimble Summer
AR = 5.7
Lexile = 810
Pippi Longstocking
AR = 5.2
Lexile = 870
Island Of The Blue Dolphins
AR = 5.4
Lexile = 1000
Turn Homeward, Hannalee
AR = 4.9
Lexile = 830
Sing Down The Moon
AR = 4.9
Lexile = 820
To look up an Accelerated Reader level, click
here.
To look up a Lexile level, click
here.
Source for the following tables can be found
here.
TYPICAL READER MEASURES, BY GRADE (source here)
| 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 |
Data for the first column of text measures came from a research study designed to examine collections of textbooks designated for specific grades (MetaMetrics, 2009). The "stretch" text measures (defined in 2010 through studies related to the development of the
Common Core State Standards for English Language Arts) in the second column represent the demand of text that students should be reading to be
college and career ready by the end of Grade 12.
TYPICAL TEXT MEASURES, BY GRADE
| 1 | 230L to 420L | 220L to 500L |
| 2 | 450L to 570L | 450L to 620L |
| 3 | 600L to 730L | 550L to 790L |
| 4 | 640L to780L | 770L to 910L |
| 5 | 730L to 850L | 860L to 980L |
| 6 | 860L to 920L | 950L to 1040L |
| 7 | 880L to 960L | 1000L to 1090L |
| 8 | 900L to 1010L | 1040L to 1160L |
| 9 | 960L to 1110L | 1080L to 1230L |
| 10 | 920L to 1120L | 1110L to 1310L |
| 11 and 12 | 1070L to 1220L | 1210L to 1360L |
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 forecasted by the reader's Lexile measure.
