In special education, multilevel models of single-case research have been used as a method of estimating treatment effects over time and across individuals. Although multilevel models can accurately summarize the effect, it is known that if the model is misspecified, inferences about the effects can be biased. Concern with the potential for model…

This single-case study tested a peer tutoring model using a visualizing strategy (story mapping) to teach struggling students better text comprehension. Three teams each consisting of a tutor and a tutee attending a fourth-grade general education classroom participated in the experiment. A short series of observations was carried out before and…

Multisite trials, in which individuals are randomly assigned to alternative treatment arms within sites, offer an excellent opportunity to estimate the cross-site average effect of treatment assignment (intent to treat or ITT) "and" the amount by which this impact varies across sites. Although both of these statistics are substantively…

Many analyses for single-case designs (SCDs)--including nearly all the effect size indicators-- currently assume no trend in the data. Regression and multilevel models allow for trend, but usually test only linear trend and have no principled way of knowing if higher order trends should be represented in the model. This paper shows how Generalized…

Some universities administer standardized tests to estimate school effects on student learning. To that end, many of those institutions choose to gather cross-sectional data (freshmen and seniors in the same academic year) rather than longitudinal data. The effects of this decision on institutional assessment results are generally unknown. The…

Eighteen special education teachers explored one prominent example of three-dimensional virtual worlds, namely Second Life. This study aimed to (a) determine their perception of the effectiveness of a systematic 7-Step Virtual Worlds Teacher Training workshop in terms of enabling them to make informed decisions about the usability of virtual…

Single-case designs (SCDs) are a class of research methods for evaluating intervention effects by taking repeated measurements of an outcome over time on a single case, both before and after the deliberate introduction of a treatment. SCDs are used heavily in fields such as special education, school psychology, social work, and applied behavior…

The constructive replication of a prespecified, cognitively mediated model of rape's impact on psychosocial health is reported using longitudinal data (see Koss, Figueredo, & Prince, 2002, for a summary of model development). Rape survivors (n= 59) were assessed four times, 3 to 24 months postrape. Structural equations modeling of baseline data…