A Systematic Review of Research on Text Difficulty in the Context of K-12 Education: From 1948 to 2024

What makes one text more difficult than another has been the interest of researchers and educators over the past century. To guide theoretical development and research directions, this systematic review sought to identify (1) the emerging research themes, (2) the methods (qualitative, quantitative, and mixed) to measure text complexity, and (3) the key findings in existing text difficulty research. We targeted empirical research on text complexity in the context of K-12 education that was conducted outside of China and published in peer-reviewed English journals. Based on these predefined inclusion criteria, we conducted a comprehensive search in the major electronic databases (e.g., EBSCO and Web of Science) and the four previous reviews (e.g., Magdalena, 2021). A total of 11,610 articles were found between 1,948 (the earliest time we could find records) and April 2024, with 10,270 articles after removing duplicates. We screened these records by titles and abstracts (592 articles remained) and then by full texts, leading to 187 articles in the final pool. Each article was coded, and the findings were synthesized. Our key findings include (1) most articles (78.0%) were published after 2010, and primarily focused on the complexity of English texts (74.3%), with a recent proliferation in other languages (e.g., Russian, Arabic, Thai, Turkish, and German); (2) more than half of the studies developed quantitative-based readability formulas (83.0%), some adopted qualitative schemes (11.0%), and reader ratings were rarely used (8.0%); (3) most studies focused on primary school and above (91.4%), and less on kindergarten (8.6%); (4) Little existing work has focused how to support students in comprehending complex texts. Future research on texts for young children using a mixed approach is warranted to support reading acquisition in a wider age range.

Keywords

K-12; Text Difficulty, Systematic Review, Empirical Research, Content Analysis

source

International Journal of Chinese Language Education; Jun 2025; Issue No. 17; p. 173-197

Language

Chinese