Knowledge is an important predictor and outcome of learning and development. Its measurement is challenged by the fact that knowledge can be integrated and homogeneous, or fragmented and heterogeneous, which can change through learning. These characteristics of knowledge are at odds with current standards for test development, demanding a high…

In this meta-analysis, we examined whether children classified with specific language impairment (SLI) experience difficulties with writing. We included studies comparing children with SLI to (a) typically developing peers matched on age (k = 39 studies) and (b) typically developing younger peers with similar language capabilities (k = six…

This meta-analysis aimed to clarify the complex relationship between repetition and second language (L2) incidental vocabulary learning by meta-analyzing primary studies reporting correlation coefficients between the number of encounters and vocabulary learning. We synthesized and quantitatively analyzed 45 effect sizes from 26 studies (N = 1,918)…

This meta-analysis reviewed research between 2012 and 2018 focused on technology-assisted second language (L2) vocabulary learning for English as a foreign language (EFL) learner. A total of 45 studies of 2,374 preschool-to-college EFL students contributed effect sizes to this meta-analysis. Compared with traditional instructional methods, the…