Scientific map of "Multigrade education" research area

The purpose of the current research is to explore the multigrade research field (multi-level class, multi-level education, etc.). This has been done through the use of scientific map drawing techniques. The research community and sample are all articles indexed in the Web of Science citation database, which were extracted and stored with a special protocol. The data were analyzed  by using VOS Viewer software. The following information was obtained from the analysis of the articles: the top authors in terms of the number of articles, Mason (5 cases), Smith (4 cases) and Burns (4 cases) and in terms of the number of citations, Shriberg, Baik, Khan, Mohammad, Sajjad, ulah and Wu (207 citations) are; Also, the top institutions in terms of number of articles are University of London (7 cases), University of Florida (5 cases) and University of Barcelona (4 cases) and in terms of number of citations Islamia College, Sejong and Sitat (each 207 citations). It is worth considering that these highly cited universities have won the first rank with only one article. The top countries in terms of the number of articles are America (47), Brazil (25) and China (15); Also, in terms of the number of citations, they are America (658 citations), China (290 citations), South Korea and Pakistan (207 citations). Also, the most frequent words in all articles; It is (multigrade), (teacher) and (education). The current software provides many tables and graphs, only a few of them are given here so that the readers can get a general understanding of the multigrade research field by studying them.