本研究以國小四年級、六年級以及國中二年級學生為受試者，並以較具建構教學取向的實作評量卷三種作為教學引導的工具，以探究不同年級而且具有不同「槓桿原理」知識的學生其學習槓桿原理公式的成效。研究結果顯示：國小四年級的學生雖然會進行實作裝置的探究，但是還沒有「覺知」槓桿原理中的基本關係；至於，六年級的學生在丙卷上呈現認知表現的「退化」現象；而國中二年級的學生大都已經學會了槓桿原理的公式。不同年齡的學習成效反應不同的認知發展現象，本文並就認知發展的觀點，探討本研究之結果在教學應用上的含意。

The present study is a cross-sectional one. The purpose of the study is through performance assessment to explore students’ cognitive development. Focusing on exploring students’ learning effects on the concept of the “law of levers”, three forms of tests were conducted, and three grades of students participated in this study. They are 37 fourth grades, 38 sixth graders, and 44 eighth graders who have different degrees of knowledge concerning the law of levers. The results reveal：1.) The fourth graders can manipulate the assessment device very well, but they are not aware of the object-relationship within the law of levers. 2.) The sixth graders have a regressive performance on the C-form test. 3.) The eighth graders have learned the principle of the law of levers. The instructional applications of the results are discussed in the study.