Abstract
The purpose of this study was to explore the effects of promotion and differentiation of writing ability on the assessment of learning potential for writing ability. The participants chosen were consisted of 10 high writing ability students and 10 low writing ability students from a junior high school in Taipei. This study adopted 2 (ability) x 2 (assessment stage) experimental design. Two-way mixed design analysis of Variance was used to verify the effects of promotion, and t-test statistics was used to test the effects of differentiation. Diagnostic interview data of writing process were analyzed by qualitative method. The results of this study indicated that the learning potential assessment promoted composing abilities in low writing ability students, while the high writing ability students would not. Furthermore, the low writing ability students needed more interventions than the high writing ability students. In addition, the learning potential assessment addressed this concern by providing direction for how and to what degree a student's writing needed to be supported.