The Lexile Framework
The Lexile Framework for Reading
The Lexile Framework for Reading, developed by educational measurement and research organization MetaMetrics®, provides a common, developmental scale and measure to match readers with resources and activities that are targeted to their ability level. Lexile measures help educators, librarians and families select books, articles and other materials that provide the right level of challenge for the reader's skills and goals, and to monitor growth in reading ability. Tens of thousands of books and hundreds of millions of articles have Lexile measures, and the number of resources with Lexile measures continues to grow. Recognized as the most widely adopted reading metric, Lexile measures are used at the school level in all 50 states. Each year, more than 30 million Lexile measures are reported from reading assessments and programs, representing more than half of U.S. students. For more information, visit www.Lexile.com.
The Lexile Framework for Reading provides educators reading measurements that are actionable and that apply to everyday classroom instruction. Make the most out of Lexile measures by downloading a free Lexile Resource Kit to help you integrate Lexiles into instruction. Download Resource Kits from the Lexile website.
How Lexile Levels Work in MyReadingLab
MRL uses The Lexile® Framework for Reading to diagnose a student's reading ability over time. It begins with a Locator Test that estimates the student's initial reading level and continues by providing readings and accompanying diagnostic tests that incrementally adjust the estimate of the student's reading level with increasing precision.
A student's initial score is just an estimate. It is determined by the student's ability but also by a host of random factors. The Lexile system re-diagnoses the student with additional readings, and it is through these additional readings and tests that the student gets a much more precise and reliable estimate of his or her reading ability. As the student reads additional selections and takes additional diagnostic tests, his or her score is incrementally adjusted based not only on his or her score on the specific diagnostic test but also by his or her history in the Lexile system. Other things equal, the more tests the user takes, the less each additional test can affect the measurement. This is because later tests represent proportionately less information on the student's ability. In other words, a student who does relatively poorly on their first diagnostic test (after they have taken the Locator Test) could see his or her score drop significantly, whereas a student who has taken many tests would see his or her score drop only marginally.
For example, consider a student who takes the initial Locator Test and receives a score of 950L. Is this a good estimate of the student's ability? Well, it is the best estimate at the time, but it still is only one piece of information. Any number of factors could have affected the results besides the student's inherent reading ability. Fortunately, the student can do additional readings and take additional Lexile diagnostic tests. Suppose he or she completes these readings, and gradually works his or her way up to a Lexile level of 1000L. The student has now taken many diagnostic tests and the Lexile system is confident in the 1000L assessment because there has been a steady change over time from the initial 950L to the final 1000L. Now, if the student took one more test, and did poorly on it, the Lexile system would view this as something of an anomaly, and weight it accordingly. The Lexile system thus adjusts the score very little in response to an isolated out-of-trend score. On the other hand, if another student scored a 1000L at the start, and on the very next test did particularly poorly, his or her Lexile measure would drop significantly. The student would have to do additional readings and take additional tests for the system to be sure of his or her reading level.
It is the ability of the Lexile system to provide readings targeted at a student's estimated reading level and also to repeatedly diagnose his or her performance over time that makes the Lexile measure such a powerful and precise estimate of the student's reading ability. This ensures that the results don't rest on fluky measurements. To take full advantage of the Lexile system, you should encourage your students to continue to do additional readings and continue to take the Lexile diagnostic tests. This will give both you and your students much greater confidence to see how well they are progressing over the course of the semester.*
*A student's initial Lexile level assessment is a point estimate, with an accompanying standard error. The error is due to the fact that the system assumes that a variety of random factors affect a student's performance. When the student takes additional tests, the Lexile level is adjusted based on two factors: the deviation of the diagnostic score from 75%, and the beginning standard error. A score above 75% will raise the Lexile level. The amount of the change is positively correlated with the standard error. Thus, a high score and a high beginning standard error will cause the Lexile level to rise a great deal. As the student takes additional tests, the standard error will drop if the test results depict a trend in student performance. This means that the Lexile level becomes less sensitive to additional score results. This is because the system becomes more confident in its predictions. Of course, if the student's test results display no trend at all, the standard error will remain high and the Lexile level will be less stable from one diagnostic test to the next.
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MetaMetrics, an educational measurement and research organization, develops scientific measures of academic achievement and complementary technologies that link assessment with targeted instruction to improve learning. The organization's renowned psychometric team created The Lexile Framework for Reading; El Sistema Lexile para Leer, the Spanish-language version of the reading framework; The Quantile® Framework for Mathematics; and The Lexile Framework for Writing. In addition to licensing Lexile and Quantile measures to state departments of education, testing and instructional companies, and publishers, MetaMetrics offers professional development, resource measurement and customized consulting services.