An appropriate estimate of statistical power is critical for the design of intervention studies. Although the inclusion of a pretest covariate in the test of the primary outcome can increase statistical power, samples selected on the basis of pretest performance may demonstrate range restriction on the selection measure and other correlated…

This study examined the effectiveness of a researcher-provided intervention with fourth graders with significant reading difficulties. The intervention emphasized multisyllable word reading, fluent reading of high-frequency words and phrases, vocabulary, and comprehension. To identify the participants, 1,695 fourth-grade students were screened…

We evaluated the reliability and validity of two oral reading fluency scores for 1-minute equated passages: median score and mean score. These scores were calculated from measures of reading fluency administered up to five times over the school year to students in grades six to eight (n = 1,317). Both scores were highly reliable with strong…

A 2-year, randomized control trial with 9th to 10th grade students with significant reading problems was provided for 50 minutes a day in small groups. Comparison students were provided an elective class and treatment students the reading intervention. Students were identified as demonstrating reading difficulties through failure on their state…