A number of studies have used mindfulness-based interventions to influence the behavior of people with intellectual disabilities, to improve their quality of life, and to reduce challenging behavior. The present review critically evaluates 18 studies and assesses the clinical and academic impact of their findings. Strengths identified included…

Combining diverse methods in a single study raises a problem: What should be done when the findings of one method of investigation conflict with those of another? The authors illustrate this problem using an example in which three study phases--quantitative, qualitative, and intervention--are applied. The findings from the quantitative phase did…

In a nonrandomized or observational study, propensity scores may be used to balance observed covariates and trajectory groups may be used to control baseline or pretreatment measures of outcome. The trajectory groups also aid in characterizing classes of subjects for whom no good matches are available and to define substantively interesting groups…