This study tested whether writing skills, knowledge, motivation, and strategic behaviors (within the context of robust writing instruction) each made a statistically unique contribution to predicting fifth-grade students’ (123 girls, 104 boys) composition quality and length on a persuasive writing task involving source material, after variance due to other predictors and control variables (reading comprehension, gender, class, and school effects) were controlled. With one exception, writing skills, knowledge, motivation, and strategic behaviors each accounted for statistically unique variance in predicting compositional quality. The exception involved writing knowledge, which did not make a unique contribution in the fall but did in the spring, when a topic knowledge measure was added. In addition, writing motivation, and strategic behaviors accounted for unique variance in composition length in the fall, and writing knowledge did so in the spring.

中文翻译：

---

写作技巧、知识、动机和战略行为预测学生在强有力的写作教学背景下的说服性写作表现

这项研究测试了写作技巧、知识、动机和策略行为（在稳健的写作教学的背景下）是否对预测五年级学生（123 名女生，104 名男生）的作文质量和长度有统计学上的独特贡献。在控制其他预测因素和控制变量（阅读理解、性别、班级和学校效应）导致的差异之后，涉及原始材料的写作任务。除了一个例外，写作技巧、知识、动机和战略行为都在预测作文质量方面具有统计上独特的差异。例外涉及写作知识，它在秋季没有做出独特的贡献，但在春季做出了贡献，因为添加了主题知识度量。此外，写作动机，