線上集體購物是一群對特定商品或服務有相同需求的消費者，透過網路藉由群體的力量提升對供應商的議價能力。在此模式中，消費者將可能感受到一些特有的風險。而回饋機制則是在電子商務中常被消費者用來降低交易風險和提升信任感的機制。
過去在一般線上購物中，已有許多關於回饋機制的研究。但在線上集體購物上卻缺乏此方面的研究。相較於一般線上購物，線上集體購物包含了更多的不確定性與風險。故，我們以實驗法的方式將回饋機制以評論式和評比式回饋機制以進行實驗的操作，藉此以了解回饋機制對線上集體購物消費者行為的影響。本研究之目的在於探討回饋機制是否影響線上集體購物消費者的認知風險和對主購的信任感，進而影響消費者加入集體購物的意圖。
本研究結果顯示，回饋機制的確會對線上集體購物消費者的行為造成影響。評比分數會影響消費者對線上集體購物的財務、心理和時間風險認知，而評論內容也會對消費者的心理風險認知造成影響。並且，主購開團經驗的豐富與否也會影響消費者的時間風險認知。消費者對線上集體購物所認知到的財務、時間風險認知會影響其對該集體購物的加入意圖。

Online group-buying means that a crowd of consumers combine with each other and massively purchase a certain object, and therefore can attain to a lower price(Kauffman et al. 2002). In group-buying transaction model, consumers usually recognized the risks specially. Therefore, the feedback mechanisms were used to reduce the risks and increase the trust.
In general electronic shopping, many past studies especially explore the use of feedback mechanisms(Dellarocas 2003; Singh et al. 1991). However, there are few studies about the effect of feedback mechanisms on online group-buying. Compare to general electronic shopping, shopping in group-buying will include more uncertainty and risk. Thus, this study will use experimental methodology to explore the feedback mechanisms that how to impact the behavior of group-buying consumers with forum and rating feedback mechanisms. Our study mainly explores whether the feedback mechanisms affect the consumers’ trust in seller’s credibility and perceived risk in group-buying, and whether the intention to join group-buying is influenced by the trust in seller’s credibility and perceived risk.
The study shows that the online group-buying consumer behavior is influenced by the feedback mechanisms exactly. The ratings affect consumers’ perceived financial risk, perceived time risk and perceived psychological risk. The forum affect consumer’s psychological risk perceived, and the experience of the initiator who initiates group-buying also affect the consumer’s time risk perceived. The intention to join group-buying is influenced by the trust in seller’s credibility and perceived risk.

目錄
第一章 緒論 1
第一節 研究背景 1
第二節 問題描述與研究動機 1
第三節 研究流程 3
第四節 論文結構 5
第二章 文獻探討 6
第一節 線上集體購物的機制 6
一、 線上集體購物的定義 6
二、 線上集體購物的協定 7
三、 集體購物網站消費者的行為 7
四、 台灣集體購物網站目前現況發展 8
第二節 線上回饋機制與消費者行為 11
一、 口碑與線上回饋機制 11
二、 線上回饋機制的種類 12
三、 正負面回饋對消費者行為的影響 14
第三節 信任與消費者行為 15
一、 信任的定義與重要性 15
二、 信任的多向度 16
三、 影響信任的因素 17
四、 信任關係發展的過程 19
第四節 認知風險與消費者行為 20
一、 認知風險的定義與種類 20
二、 消費者在集體購物所面臨的不確定性與風險 22
三、 認知風險對消費者行為的影響 23
第三章 研究架構與方法 27
第一節 研究架構 27
第二節 研究假說 30
第三節 研究變數與操作性定義 34
一、 回饋機制 34
二、 認知風險 34
三、 主購信任 35
四、 加入意圖 35
第四章 實驗設計 36
第一節 實驗任務情境 36
第二節 實驗產品 36
第三節 實驗操作 38
第四節 問卷設計 42
第五節 實驗程序 44
一、 實驗流程 45
二、 實驗後 46
第五章 資料分析 47
第一節 基本資料敘述統計 47
第二節 問卷信效度分析 49
一、 探索性因素分析(EFA) 49
二、 信度分析 50
三、 驗證性因素分析(CFA) 51
第三節 假設檢定 52
一、 回饋正負面程度的不同對認知風險與信任感的影響 53
二、 認知風險、信任感及加入意圖之間的關係 57
第四節 研究假設檢定彙整 58
第五節 整體結果之討論 60
第六章 結論與建議 64
第一節 研究發現與結論 64
一、 正面評論減少心理風險；負面評論增加心理風險 64
二、 正面評比多 認知風險越低；主購開團經驗越多 時間風險越低 64
三、 對主購信任越高 財務風險越低 65
四、 財務風險、時間風險及主購信任感 為影響集體購物決策之因素 65
第二節 研究貢獻 66
一、 學術貢獻 66
二、 實務貢獻 66
第三節 研究限制 67
第四節 研究方向建議 67
參考文獻.. 69
附錄－實驗系統介紹 76

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