Trends in Categorization Research in Writing: A Systematic Review

Many researchers have argued that customized learning opportunities should be provided considering individual differences in the educational environment. The most effective way to consider students' individual differences is to find and classify specific patterns among them. In particular, considering that writing research ultimately provides basic information for effective writing instruction, it is required to derive learners' writing profiles and find suitable teaching methods according to those different types. For this purpose, the current study aims to analyze the trends in writing categorization research conducted in the domain of language learning. We adopted a systematic review as research methodology to examine research trends strictly and efficiently and analyzed writing categorization research in terms of its topic, method, purpose, etc. The research procedure based on systematic review was carried out according to the flow chart and the criteria for selecting and excluding literatures, suggested by the PRISMA group. First, a total of 1,026 research articles were collected from two representative research databases in the field and additional searches through reference review. Subsequently, we went through a step-by-step selection stage of deduplication, primary filtering, and secondary filtering under the selection and exclusion criteria. We then decided a final list of research articles that could be properly classified as categorization research in writing through abstract and full-text review. The content analysis technique was applied to the selected research articles. They were coded based on following 7 criteria: research methodology, participant, topic of research, research area, targeted/categorical variable, purpose of analysis, and whether there is a difference in quality/level between the subtypes of each categorical variable. From these coding results, we could investigate the overall trends of categorization research in writing and find the implications for the design of follow-up studies and the application of writing education.