Reading and Writing Relations Are Not Uniform: They Differ by the Linguistic Grain Size, Developmental Phase, and Measurement

We conducted a meta-analysis to investigate reading-writing relations. Beyond the overall relation, we systematically investigated moderation of relation as function linguistic grain size (word reading and spelling versus comprehension written composition), measurement (e.g., multiple choice, open-ended, cloze), composition writing quality, productivity, fluency, syntax), developmental phase (grade levels proxy). A total 395 studies (k = 2,265, N 120,669) met inclusion criteria. Overall, were strongly related (r .72). However, differed depending on subskills such that word =.82) whereas moderately =.44). In addition, reading-spelling was stronger for primary-grade students than university students/adults =.69). The with composition—reading measured by choice open-ended tasks had quality oral retell tasks; moderate relations vocabulary, syntax, conventions but weak productivity fluency. Relations tended be when reliability higher, between alphabetic languages .83) Chinese .71). These results add important nuances about nature writing.