There's very little research on how to effectively teach writing and few pre-service teachers explicitly learn how to teach it in credentialing programs. And yet good writing has become a central skill for most subject areas, including math and science, where teachers are now asking students to explain their thinking. Many teachers use model texts and writing assignments rooted in students' lived experiences to give kids practice writing. Proponents of this approach say too much focus on grammar and sentence structure stunts the individual's voice. On the other side of the debate are people like Judith Hochman, who believes writing should be taught starting at the sentence level.
The most recent National Assessment in Educational Progress (NAEP) data shows that three quarters of both 8th and 12th graders are not proficient in writing. It's clear that teaching writing is an area of growth for American schools, but what is the right approach? Instruction that blends the technical aspects of writing with inspiring ideas and content may be the best way to go. And Dana Goldstein writes in her New York Times article that something in-between is supported by the research that does exist on teaching writing:
Before writing paragraphs — which is often now part of the kindergarten curriculum — children do need to practice writing great sentences. At every level, students benefit from clear feedback on their writing, and from seeing and trying to imitate what successful writing looks like, the so-called text models. Some of the touchy-feel stuff matters, too. Students with higher confidence in their writing ability perform better.
All of this points toward a synthesis of the two approaches. In classrooms where practices like freewriting are used without any focus on transcription or punctuation, “the students who struggled didn’t make any progress,” Dr. Troia, the Michigan State professor, said. But when grammar instruction is divorced from the writing process and from rich ideas in literature or science, it becomes “superficial,” he warned.
https://www.nytimes.com/2017/08/02/education/edlife/writing-education-grammar-students-children.html