Until now, the conventional approach using two distinct groups, experimental and control, continues to dominate research, especially education research. Researchers, particularly those who are active in this domain, readily recognise this pattern when surveying literature. This article explores the use of the Solomon four-group design as a…

Experimental designs in the social sciences have received increasing attention due to their power to produce causal inferences. Nevertheless, experimental research faces limitations, including limited external validity and unrealistic treatments. We propose combining qualitative fieldwork and experimental design iteratively--moving back-and-forth…

This study was designed to assess the impact of a decision-making curriculum (PEER-DM) on the social peer relationship knowledge and self-protective decision-making skills of adolescents with disabilities in hypothetical situations involving negative peer pressure. A randomized design was used to assign students with disabilities from…

The association made between the meaning, spelling, and pronunciation of a word has been shown to help children remember the meanings of words. The present study addressed whether the presence of a target word in Braille during instruction facilitated vocabulary learning more efficiently than an auditory-only instructional condition. The authors…

In 2003, Chicago launched "Double-Dose Algebra," requiring students with pretest scores below the national median to take two periods of math--algebra and supplemental coursework. In many schools, assignment to Double Dose changed the peer composition of the algebra classroom. Using school-specific instrumental variables within a…

Separate selection and pretesting of students eliminate regression effects in the pre-post achievement gain measured in the RMC Model--A method of program evaluation. (CP)

The biasing effects of a pretest on subsequent post-test results were investigated in two experimental studies. In general, the results argue for using designs without pretests. (Author/JKS)

The problem of the appropriate comparison group for bereavement studies is discussed. The use of the retrospective pretest design is illustrated through a longitudinal study of bereavement outcome following pregnancy loss, involving 138 bereaved women and a comparison group of 215 currently pregnant women. (SLD)