Martine van der Pluijm

33 Activities and strategies – a review of empirical interventions (the type of activity used to create the necessary environment and possibilities for interaction between parent and child, i.e., shared reading, play, talk, or writing activities), intervention strategies (the type of strategies used during the intervention activity aimed at strengthening oral language development, i.e., asking open questions, expanding sentences, following the child’s interests), and mode of delivery of the intervention (description of how the intervention activities and strategies are transferred to the parent). In the third phase, we examined reference lists of recent reviews and meta-analyses (Bakker et al., 2013; Manz et al., 2010; Mol et al., 2009; Reese, Sparks, & Leyva, 2010; Van Steensel et al., 2011) and previously selected articles. We found another 129 publications using this snowball method. Of these 129 publications, 27 were not obtainable, and 96 were excluded based on the inclusion and exclusion criteria. This resulted in six additional publications. In the fourth phase, the selection of 32 studies was discussed with the second and third author, and codes were adapted to reach full consensus. This resulted in a selection of 27 publications. To provide an update of the search, a new electronic search was carried out in October 2016, which produced 92 new publications. In this final phase, one more study was identified as relevant based on our criteria, resulting in a total of 28 publications. RESULTS Our analyses of the 28 studies are presented in three tables. Table 2.1 presents the characteristics of the selected studies and reported effects on oral language development. Table 2.2 lists the activities and strategies used in the interventions, and Table 2.3 presents the modes of delivery for the activities and strategies in each of the selected studies. Below, we explain the used definitions and coding procedure. We distinguished two main types of interventions: ‘shared reading’ and ‘other home activities’. Shared reading mainly included parent-child shared book reading activities. Other home activities included play, talk, craft, write, letters, or phonemic practice. Some studies focused on one activity, others on several activities that could consist of shared reading as well. We categorized interventions as other home activities when shared reading was included but not emphasized. We classified 12 studies as shared reading and 18 interventions as other home activities. Two studies were classified in both types of interventions because they reported different experiments that used different types of activities. In Table 2.1, we distinguish six types of measurements for oral language development. Nine studies reported posttests on oral language development by using the amount of oral language production, three studies used curriculum dependent tests, 17 used standardized