视觉单通道还是视听双通道?——通道效应的元分析

Visual text or narration? Meta-analysis of the modality effect in multimedia learning

多媒体学习中的通道效应认为,学习者对"画面+声音解说"组成的视听双通道材料的识记或理解效果要好于"画面+视觉文本"组成的视觉单通道材料,而逆转通道效应则发现了与之相反的结果。针对以往研究缺陷,重新采用元分析技术,以保持测验和迁移测验作为结果变量,考察通道效应的稳定性。经文献检索、纳入与排除后,共获91篇符合元分析的文献。经数据事先合并处理后,保持测验上生成94个独立效应量(8088人),迁移测验上生成83个独立效应量(6664人)。主效应检验发现:视听双通道在保持测验(d=0.24)和迁移测验(d=0.25)上均显著高于视觉单通道;调节效应检验发现:呈现步调、画面动态性和材料时长在保持测验和迁移测验上均对通道效应起到调节作用,通道效应主要在系统步调(d_(保持)=0.43,d_(迁移)=0.44)、动态画面(d_(保持)=0.50,d_(迁移)=0.59)及短时材料(d_(保持)=0.38,d_(迁移)=0.33)条件下出现;所有结果均未发现逆转通道效应。结论认为:相比视觉单通道,当图文信息以视听双通道呈现时更有利于促进学习者对多媒体学习材料的识记和理解,支持了多媒体学习认知理论;呈现步调、画面动态性以及材料时长是通道效应的重要边界条件。

The modality effect in multimedia learning showed that learning outcomes were enhanced if words were presented in an audial format with pictures, rather than a visual format（see Mayer, 2009）. However, research on the reverse modality effect indicated a totally opposite result（e.g. Crooks, Cheon, Inan, Ari, Flores, 2012; Tabbers, Martens, van Merri？nboer, 2004）. A meta-analysis based on 91 empirical studies was conducted to investigate the effect of text modality on both retention and transfer tests. After pooling data preliminarily, ninety-four independent effect sizes（8088 participants） were finally included in retention-related meta-analysis while 83 independent effect sizes（6664 participants） in transfer-related meta-analysis. The results suggested that participants who learned from narration outperformed those who learned from visual text both on retention test（dretention = 0.24） and transfer test（dtransfer = 0.25） with different effect sizes from Ginns＇ s（2005）. Further moderator analyses indicated that modality effect on learning outcomes was significantly moderated by the pace of presentation, dynamism of pictures and duration of learning materials. Specifically, the modality effect occurred mainly in conditions of system-paced presentation（dretention = 0.43, dtransfer = 0.44）, dynamic pictures（dretention = 0.50, dtransfer = 0.59） and short learning materials（dretention = 0.38, dtransfer = 0.33）. All of the results didn＇t reveal a reverse modality effect. The replicated strong modality effect suggested that performance on recall and comprehension tasks was better when words and pictures were presented in a dual modality, rather than a single one, which supported Mayer＇s Cognitive Theory of Multimedia Learning（CTML）. Moreover, the pace of presentation, dynamism of pictures and duration of learning materials should be considered as vital boundary conditions of modality effect.