廣告中介模式自80年代提出以後，經多次修正或重新詮釋，目前模式的適合性，高信度及結構的完整，似已成廣告效果研究之主要模式之一。 然而對高意象屬性的公益形象廣告目前鮮有研究出現，是否廣告中介模式仍適合解釋闡明公益廣告？涉入程度是否影響廣告效果？四種不同解釋模式中，公益廣告較適合之何種模式來解釋呢？此為本研究之三大重點。透過實驗設計，針對學生及企業經理人之調查，以LISREL方法檢測後，發現DMH模式較適合解釋公益廣告，顯示由於公益廣告強化了品牌形象，使得品牌形象及對廣告態度產生交互作用。

The role of attitude toward the as the mediator of advertising effectiveness has been discussed and modified many times since 1980. The fitness of model, reliability of model comparison, and structural completeness of model has become a main research stream of advertising effectiveness. However, there exists an issue that whether public-benefit advertising can be explained and tested by mediator model. After an experimental design on 120 graduate students and 130 businessman through the LISREL test. It is found that involvement do have a strong influence on the model and the goodness of fit on the Public-benefit advertising is also reasonably high. Moreover, the dual mediation hypothesis (DMHI) of mediator model elaborates public-benefit advertising well.