The study took place in five Head Start classes from three Head Start centers in the Roanoke Valley in Roanoke, Virginia.
The study began with 97 low-income four- to five-year-old children. Four children were excluded from the study before assignment because of absences, and an additional 15
children were lost to attrition after assignment, leaving a sample of 78 children. The original sample of 93 children had a mean age of 4.6 years, 55% were female, and 17%
were receiving speech-language services. The children were grouped into triads based on their summed pretest score, and one child from each triad was randomly assigned
to the intervention and comparison conditions.
The study included two intervention groups: software with programmed instructional interaction with a speech-language clinician (or software with enhancement) and software
without the programmed instructional component (or software without enhancement). The software used was from the Words and Concepts series (Words and Concepts I, II,
and III ), designed to teach children about nouns and concepts. In the software with enhancement condition, the children and the clinician interacted with the computer (that is,
the clinician asked questions related to discourse skills and encouraged verbalization of responses to any questions from the clinician or the computer) to improve discourse skills
(that is, receptive and expressive language). In the software without enhancement condition, the clinician gave the children instructions about how to use the software program
to enhance their receptive vocabulary and concepts. In both conditions, children primarily participated in pairs twice weekly for 20 minutes a session over a period of 12 weeks. The two groups were combined by the WWC for this review to determine the overall rating of effectiveness. However, the WWC reports findings for the two intervention groups
versus the comparison group separately in Appendix A4 and reports findings for the comparison between the two intervention groups in Appendices A5.1 and A5.2.
Children in the no-treatment comparison group received language enrichment through the regular Head Start curriculum, including classroom activities (for example, housekeeping,
circle time, dramatic play, finger plays, story time, and songs) and characteristics of the classroom environment (for example, labeling of classroom items). The same
comparison group was used for both the software with enhancement and software without enhancement conditions.
The primary outcome domain was children’s oral language, which was measured by two standardized tests: the Preschool Language Assessment Instrument (PLAI-I, PLAI-II,
PLAI-III, PLAI-IV, and PLAI-Composite) and the Peabody Picture Vocabulary Test-Revised (PPVT-R). (See Appendix A2 for more detailed descriptions of outcome measures.)
Support for implementation
The intervention was implemented by five student speech-language clinicians (two undergraduate students and three graduate students), who were trained and supervised by
the researcher. Each classroom in the study had access to a speech-language clinician.