Martine van der Pluijm

32 Chapter 2 METHOD We conducted electronic searches in PsycArticles, PsycINFO, PsycBOOKS, and ERIC. The searches were limited to the period 2000-2016. The reason for this limitation is that the twenty- first century can be considered a turning point in the scope of family literacy research (Wasik & Herrmann, 2004). Since the 1990s, there has been a growing awareness that the quality and quantity of informal language use in the family is of importance for young children’s oral language development. Family environments are increasingly regarded as a primary learning environment, whereas schools are regarded as a secondary learning environment (Bronfenbrenner, 1977; Clay, 1993; Dickinson & Tabors, 1991; Neuman & Dickinson, 2001; Reese & Gallimore, 2000; Sénéchal, 2012). Weworked in five phases. In the first phase, whichwas conducted in January 2015, we conducted an automatic search of family literacy interventions. We combined each of five key terms family literacy, parental involvement, home-based support, home environment, home literacy with each term of the following three groups 1) parental strategies, language interventions, language development, oral language, 2) low education, lower-educated parents, low literacy, illiteracy, 3) impact, effect, influence. The results of the first phase comprised 2172 publications. We then limited our search to the age group of 3 to 8 and the English language, which resulted in 1082 publications. In the second phase, a further selection was made based on reading the abstracts and selecting interventions that met the following criteria: 1) interventions in which parents were coached to stimulate their children’s oral language development, 2) posttests in which oral language development was the dependent variable, 3) education levels of participating parents were reported and 4) articles appeared in English language journals and dissertations. Since few intervention studies target oral language development involving lower-educated or low-literate parents (Manz et al., 2010; Reese, Leyva, Sparks, & Grolnick, 2010), no inclusion criteria were formulated concerning the research designs. We, therefore, included all types of intervention studies, allowing important findings for future (more rigorous) testing. This resulted in 182 publications. We used the following four exclusion criteria: 1) interventions addressing children with specific learning or developmental problems or parents with specific psychological or behavioral problems, 2) interventions containing no clear information about effects, 3) interventions containing no clear information about activities and strategies used and 4) interventions containing no clear information about the modes of delivery of the intervention. Another inclusion criterion was that our selected studies had to supply the following information: effects of the intervention (posttests of oral language development of children), intervention activity