價值增加模式運用於教師效能評鑑之探討

Inquiry on Teacher Effectiveness Evaluation with Value-Added Models

本文透過文獻探討採用學生測驗成績進行教師效能評鑑的發展脈絡與議 題，美國的教師評鑑近年來倡行實施直接採用學生在標準測驗中的評量分數 的價值增加模式（VAM），VAM 是一項以學生在標準化測驗的成績來量化教 師效能的統計工具，支持者認為可以把特定教師價值增加的程度獨立出來， 可以區分教師有效能或無效能，但批評者認為價值增加評估是不可靠的。綜 合文獻，本文提出VAM討論的議題包括：1.教師與學生的非隨機分配、2.不穩 定的教師成就評量結果、3.教師效用難以獨立、4.窄化課程與教學、5.不利教 師協同與合作、6.邊際誤差的問題、7.忽略學生需求、8.資料錯誤的後果，最後 本文提出採用VAM進行教師效能評鑑的建議，包括：1.避免高比重的價值增加 評鑑、2.注意評鑑的要素、3.較適用於群體評鑑、4.用做教師專業發展計畫、 5.減少誤差的影響和6.對評鑑結果進行檢視及評鑑。

The objective of this paper is inquiry the context and issuses about using student test scores to evaluate teacher effectiveness. In recent years， Value-Added Models (VAM) have been adopted to evaluate teachers in USA. Advocators claim that VAM is useful when one wants to know how a particular teacher’s contributions to student improvement compare to the average teacher， then they can distinguish “effective” or “ineffective” teachers. Therefore， more student Value-Added scores more teaching effective. Opponents considered that VAM is unreliable and could not be used to rank teachers. Finally， there are many suggestions listed in this paper ， includeing: (1). avoid high weights for Value-Added evaluation; (2). pay attention to all components of the evaluation; (3). be appropriate used for teams evaluation; (4). be one of the teacher professional development plans; (5). reduce the influence of error and (6). continually evaluate the evaluations.