線上口碑片面性效應之研究

Abstract

口碑的片面性是網路口碑的重要屬性之一，過去研究也發現其對於產品歸因及感知助益性有正向的影響（同時提到正負面的口碑會比只提到正面或負面的口碑更歸因到產品或更有幫助）。由於網路口碑的匿名性使得消費者難以從評論者的身份判斷其可信度，而需轉向口碑內容品質來評估。由此可知資訊完整度以及感知真實性對於網路口碑的重要性是不言而喻的，然而現存有關口碑片面性的文獻卻少有相關的研究。因此本研究調查兩面口碑是否比片面口碑更能提升資訊完整度、感知真實性。儘管眾多的研究支持片面性效應，仍有文獻不一致的情況出現;這代表可能有調節因子的存在，Nelson的產品類型（1970）便可作為調節因子來解釋這種不一致性。搜索品評論的可比較性和更客觀的特性將激勵消費者更願意處理，因為他們期望投入的努力將得到回報。反之，體驗品評論的需要消費者自身感官評估的性質會降低消費者的處理動機，因為他們認為不值得付出認知成本。採用推敲可能性模型理論，本研究假設由產品類型引起的消費者動機差異會導致片面性效應的不一致。本研究提出在資訊完整性，感知真實性，產品歸因和感知助益性方面，在搜索品的情況下，片面性效應將比在體驗品下來得更強。實證結果支持了本研究的大多數假設，並推動對片面性效應及其調節因子產品類型的理論解釋。

Review sidedness has found to positively affect perceived helpfulness and product-related attribution. Consumers cannot judge the reviewer's credibility due to eWOM anonymity; instead, they would focus on the review quality to form credibility. The importance of information completeness and perceived truthfulness in eWOM is self-evident. Yet, little evidence of these two factors can be found in the research of review sidedness. Hence, we investigated whether the two-sided review would boost completeness and truthfulness more than the one-sided review. Still, other scholars find the sidedness effect not significant; moderators like Nelson's product type have emerged to explain this inconsistency. The comparable and objective manner of search good reviews would motivate consumers more to process since they expected the effort devoted would pay-off. Vice versa, the sense-required nature of experience good review would make the consumers less motivated to process inasmuch as they do not consider it is worthy. Adopting ELM, we postulated the presence of the sidedness effect results from the difference of consumer’s motivation caused by product type. We proposed the sidedness effect would be stronger under search good than experience good condition on information completeness, perceived truthfulness, product-related attribution, and perceived helpfulness. The empirical results support most of our hypotheses and advance the theoretical explanation for the sidedness effect and product type.