Despite their long trajectory in the social sciences, few systematic works analyze how often and for what purposes focus groups appear in published works. This study fills this gap by undertaking a meta-analysis of focus group use over the last 10 years. It makes several contributions to our understanding of when and why focus groups are used in…

When performing a meta-analysis unexplained variation above that predicted by within study variation is usually modeled by a random effect. However, in some cases, this is not sufficient to explain all the variation because of outlier or unusual studies. A previously described method is to define an outlier as a study requiring a higher random…

Within the emerging field of research on education for sustainability (EfS), case studies are an important if not the predominant research approach, although often criticised for its lack of internal and external validity and a tendency to draw conclusions with insufficient rigour. While, basic concerns have been expressed and discussed in an…

Studies that explore pedagogical content knowledge (PCK) in the field of mathematics education date back to the turn of the century in Turkey. In recent years, studies on PCK have gained momentum. Master's theses and doctoral dissertations have been written on PCK. In this context, there is a need to analyze the studies on PCK in Turkey to…

Research conducted over the past decade has consistently reported no significant differences in learning outcomes for students of fully online or face-to-face (F2F) instruction. Only a small number of these studies, however, have focused on courses in second language (L2) teacher preparation programs. Even fewer studies have compared the impact of…

Problem-based learning (PBL) is an instructional strategy that is poised for widespread application in the current, growing, on-line digital learning environment. While enjoying a track record as a defensible strategy in face-to-face learning settings, the research evidence is not clear regarding PBL in on-line environments. A review of the…