There has been a significant increase in the use of secondary data sets. Many such data sets purport to be nationally representative. Secondary data sets include research commissioned by the National Center for Education Statistics, the Centers for Disease Control, and other public entities. Research increasingly utilizes these secondary data in…

In the current study, momentary time sampling (MTS) and partial-interval recording (PIR) were compared to continuous-duration recording of stereotypy and to the frequency of self-injury during a treatment analysis to determine whether the recording method affected data interpretation. Five previously conducted treatment analysis data sets were…

The possibility of differential sex proportions as a confounding factor in the Lovaas (1987) study is raised. It is argued that the chi-square analysis was inadequate and that the appropriate comparison should be made between the experimental and the control group using population data to estimate expected cell frequencies. (Author/CR)