本研究探究直接教學法（Direct Instruction, 簡稱DI）對二年級識字困難學童學習單字與字詞造句應用之成效。採單一受試跨行為多試探設計，教學成效複製於快速唸名缺陷、快速唸名與聲調覺識雙缺陷以及無認知缺陷三位不同認知表現類型之識字困難學童。單字教學依照DI 教學原則進行，並將字音與字形相似的字，分散在不同教學節次內進行。字詞應用造句乃依照DI 詞彙教學，根據不同詞彙性質設計「定義」、「圖示」與「同義詞的使用」三種方式教導，並以正反例不斷提問，以幫助學童釐清詞彙意義與使用方式。研究結果顯示，學童接受教學介入後，在識字與字詞造句應用上，均有正向的進步趨勢。識字表現亦隨著介入而趨於穩定，然聲調及快速唸名雙缺陷學童之進步趨勢，最易受聲調不同字的介入影響。字詞造句應用的進步成效則反應在學童對詞彙意義理解的精確性及正確使用上。研究者根據此結果進行討論，並針對未來教學與研究提出建議。

This study investigated the effect of Direct Instruction (DI) on children with reading difficulty. A multiple-probe design examined students' performance in character reading and sentence forming over time. Three second-grade children with reading difficulties, including one with naming deficit, one with double deficits in naming and tonal awareness, and one with neither naming nor tonal awareness deficit took part in this teaching research study. Character teaching was designed according to the principle of mastery of DI, and characters with similar pronunciation and orthography were allocated in different lessons. The design of sentence forming was divided into three teaching methods according to DI, namely, “identification,” “picture indication,” and “synonyms.” The teacher guided the students to compare correct versus incorrect examples through the process of question and answer. The results revealed that all three students had made significant improvement in character reading and sentence forming. The students' improvement in learning to read characters continued steadily, except for the student with double deficits, who continued to have difficulty with characters with similar pronunciation but different tones. The students' improvement in sentence forming was reflected in the discrimination of vocabulary meaning and the appropriateness of application. Implications for pedagogy and future research directions are provided.