Setting
The study included 10 Head Start preschool classrooms in Eastern Pennsylvania and 18 pre-K classrooms in Central Tennessee. About nine students per classroom participated in the study.
Study sample
The authors reported that the students in the study were 55 percent Black, 23 percent Hispanic/Latino, 1 percent Asian, and 14 percent White, and 7 percent other race or multiracial. The average age was 59 months (4.9 years), ranging from 39 months to 66 months. Most students in the sample were low-income. In the Pennsylvania classrooms, all children were low-income, while in Tennessee, low-income students were prioritized for enrollment. Fifteen percent of the sample were English learners, and there was no report of children having learning disabilities.
Intervention Group
The intervention condition for this review is the aggregated sample of the guided play and directed play intervention groups. In both the guided play and directed playgroups, students received the intervention in small groups led by an outside intervention specialist. The intervention lasted two weeks (8 days), with each week having 4 consecutive days of sessions. Each session had two phases: (1) book reading and (2) play. In the book reading phase, the intervention was exactly the same for the guided play and directed playgroups. Intervention specialists followed a script to guide 10 minutes of reading. The books used included 10 target words, which were explicitly defined and taught by the intervention specialist during reading, along with 3-5 exposure words, which were included in the book but not explicitly taught, and 8 control words. The instruction on the target word began with a child-friendly definition, additional conceptual information, use of a gesture, and tied to the pictures in the book. One book was read in the first week while a second book was read in the second week of the intervention sessions. The books either covered a dragon or farm theme. After reading the book, the intervention specialist reviewed the story and used picture cards to review the target words. Over time, the children were asked to produce more of the words themselves. The scripts also included comprehension related discussion questions, which grew in difficulty over time as children became more familiar with the story. Following the book-reading phase, there were 10 minutes of playtime in both groups. This level of instruction during this phase varied across the two groups. In the directed playgroup, children were asked to reenact the story from the book. The directed play was done by the intervention specialist who used a script to lead the activity. The script included at least three of the target words and their definitions. In the guided playgroup, the children could choose how to spend their playtime; the intervention specialist did not have a script for this group but would follow the children’s lead on the play activities. The intervention specialist would join the children’s play activities and incorporate target words into the conversations using a definition, close-ended question (meaning one with an easy answer drawing on the definition or the story), and open-ended question (meaning one with a more nuanced answer that did not have a single right answer and required students to think more deeply).
The three conditions were delivered by trained intervention specialists. There were nine intervention specialists, all of whom were female. They had a background in working with young children. Some were previously preschool teachers and others worked at libraries or bookstores.
Comparison Group
The comparison in this study was free play. The duration and timing of sessions was the same as the intervention group. In the free play condition, the book reading portion of the session was the same as the two intervention groups (guided play and directed play). Free play differed from the other two conditions in the play portion of the session. For 10 minutes, children played with the toys in whichever manner they chose. The intervention specialist did not actively engage with students as they played and did not incorporate the target words into the play activities.
Support for implementation
Intervention specialists led the activities for each of the groups (free play, guided play, and directed play). They attended two to three training sessions that were three to four hours long. During the training sessions, they reviewed the scripts and practiced leading the activities using role-playing exercises.