本研究以個案研究法探討四位教學經驗與職前學科訓練迥異的國小自然科教師;具數理背景與非數理背景的資深教師周耋師與黃老師、初任教師李耋陃與安老師，對「地球運動」單元之教學知識、實務與成效。收集資料的方法有:教室觀察、教師問卷、訪談、學生問卷與測驗和學習氣氛量表等。分析結果顯示:資深教師對單元知識發展向度之了解高於初任教師，在教學實務上則是資濘教師以多重證據探討概念，教學時能與學生學習過的課程相連貫，有較佳的教室管理模式與多元化的評量方法。在教學成效上營造了較佳的學習環境，但在概念測驗之表現上，則是發現與教師背景無一致的結果。初任非數理背景之安老師，在教學前、中均有迷思概念之出現。而李老師超強的地科景則在嗶元知識的結構向度上有最佳的顯現。

　　　　　 There were four paticipatns in this study: two experienced teachers, one with science major and the other not; two novice teachers, one with science major and the other not teachers, one with science major and the other not. The purpose of the study was to explore the four teachers' instruction of the unit Motion of the Earth". Data were collected by means of classroom observation, teachers' questionnaires, student's questionnaire, tests, and interview. The findings were as follows: twp experienced teachers understood the development of knowledge, represented concepts with multievidence, instruction connected with student's past learned, had better classroom management at multimethods of evaluation, built the positive learning climate. The novice teacher with weak science had some misconceptions, and the other novice teacher with strong science had best structural knowledge.