2. Introduction Multilevel linear model Hierarchical linear model, HLM The intervention may well be delivered and have effects at more than one level, sometimes unwittingly. If we drop a tone into water the maximum effect is seen where the stone hits the water, but the ripples go outwards for some distance. 2
13. Project Charlie (Drugs education program) A two-form-entry school Intervention: class level Classification of intervention: random Pre-test & post-test 13 Level two Level one
17. Practical issues:leakage 短期而言,無論是within school / between schools的比較,操弄是有效的 長期而言,計畫效果變得不太明顯,只在between schools有顯著 假如leakage可以測量,可將其包含在階層一方程式中,給予一些指標表示其影響的幅度 例如也可比較階層一和階層二的effect size,但這又可能混淆了有沒有隨機分派所造成的誤差 18
18. Discussion The level of delivery of an intervention is not straightforward. Interventions frequently have an effect at more than one level is probably a common phenomenon, both in education and in other social science contexts. 19
19. References Plewis, I., & Hurry, J. (1998). A multilevel perspective on the design and analysis of intervention studies. Education Research and Evaluation, 4(1), 13-26. 邱皓政(譯)(2006)。多層次模型分析導論。台北市:五南。(Kreft, I., & de Leeuw, J., 1998) 郭志剛(譯)(2008)。階層線性模式。台北市:五南。(Raudenbush, S. W., & Bryk, A. S., 2002) 劉子鍵、陳正昌(2009)階層線性模式。載於陳正昌,程炳林,陳新豐,劉子鍵(主編),多變量分析方法-統計軟體應用(頁423-452)。台北市:五南。 20