This study examines the initial word reading performance of fourth-grade struggling readers and the extent to which differing levels of word reading performance at pretest influenced their response to reading interventions. A large group of students with significant reading comprehension difficulties (N = 481) were classified into three clusters…

When two groups, initially dissimilar, undergo different treatments, can subsequent differences be partitioned in such a way that the difference between the two treatments is unbiased? This is the central problem of this paper, and it is confronted by the examination of two levels of information using a Follow Through Evaluation. The first…