本研究採用網路問卷調查法,分別就網路使用者之搜尋產品類型、認知需求與知覺風險三方面來檢視關鍵字廣告效果。而關鍵字廣告效果在本文中分為三種,一為「知曉效果」,指的是對關鍵字廣告的注意程度;其次是「定址效果」,指的是點閱關鍵字廣告的行為;第三為「轉換效果」,指的是因為參考關鍵字廣告而產生的消費行為。研究結果顯示:(1)關鍵字廣告的效果以知曉效果最明顯(最易產生),定址效果次之,轉換效果則相對最差。(2)關鍵字廣告之知曉效果、定址效果、轉換效果皆會因為搜尋產品類型之不同而有別,低涉入產品比高涉入產品效果更好。(3)個人認知需求對於關鍵字廣告之知曉效果不具有顯著預測力,但能夠顯著預測關鍵字廣告之定址效果與轉換效果,且個人認知需求越低,廣告效果越好。(4)網路使用者感知關鍵字廣告之知覺風險,對於關鍵字廣告的知曉效果、定址效果與轉換效果皆具有顯著預測力,且網路使用者感知關鍵字廣告之知覺風險越低,廣告效果越顯著。 By using online survey, this study tried to find the influence on keyword advertising effect by exploring online users' searched product categories, need for cognition, and perceived risk. The keyword advertising effect in this paper was divided into three categories. "Awareness efficiency" is referring to the level of attention to keyword advertising. "Locatability efficiency is referring to the clicking behavior toward the keyword advertising. "Conversion efficiency" is referring to the consuming behavior contributed by the keyword advertising. The results show that the most salient effect is "awareness efficiency," followed by "locatability efficiency," and "conversion efficiency" is relatively the least. In addition, all of the above three efficiencies are significantly different while comparing the high and low involvement product, the effects of searching the low involvement products is more salient than the effects of searching the high involvement products. The need for cognition can't predict the "awareness efficiency," but can predict the "locatability efficiency" and the "conversion efficiency." The lower the "need for cognition," the higher the keyword advertising effect will be. Furthermore, "perceived risk" can significantly predict the advertising effect, the lower the "perceived risk," the higher the keyword advertising effect.