Implicit theories have important implications for students' achievement goals and academic achievement. The Writer(s)-within-community model by Graham (2018) postulates that motivational beliefs stored in the long-term memory, such as implicit theories and achievement goals, influence how one approaches a writing task. Notwithstanding, few empirical studies examined the relations among implicit theories, achievement goals, and writing performance. In this study, we sought to examine the structural relations among implicit theories, achievement goals, and writing performance of Portuguese students in grades 5 to 8 (M_age = 11.80, SD = 1.5). In addition, we aimed to test whether the relations among implicit theories, achievement goals, and writing performance varied across two text genres, and for girls and boys. Our results showed that more incremental theories in writing were associated with a greater pursuit of mastery goals as well as with higher text quality. Moreover, a greater endorsement of mastery goals was associated with higher text quality, whereas a greater adoption of performance-approach goals was linked to lower text quality. These relations remained stable for girls and boys and across narrative and opinion texts. Overall, these findings confirm the pivotal role of motivation-related variables in predicting students' writing performance.

内隐理论对学生的成就目标和学业成就具有重要意义。Graham (2018) 的社区内作家模型假设存储在长期记忆中的动机信念，例如内隐理论和成就目标，会影响一个人完成写作任务的方式。尽管如此，很少有实证研究考察内隐理论、成就目标和写作表现之间的关系。在这项研究中，我们试图检验葡萄牙 5 至 8 年级学生的内隐理论、成就目标和写作表现之间的结构关系（M_年龄 = 11.80，SD = 1.5)。此外，我们旨在测试内隐理论、成就目标和写作表现之间的关系是否在两种文本类型以及女孩和男孩中有所不同。我们的研究结果表明，写作中更多的渐进理论与对掌握目标的更大追求以及更高的文本质量相关。此外，对掌握目标的更大认可与更高的文本质量相关，而更多地采用绩效方法目标与更低的文本质量有关。这些关系对于女孩和男孩以及叙事和意见文本都保持稳定。总体而言，这些发现证实了动机相关变量在预测学生写作表现中的关键作用。