The research question examined in this paper is whether or not product price can be used as a proxy to predict how customers' trust will be influenced by different trust-assuring arguments displayed on a business-to-consumer e-commerce Web site. Drawing from the elaboration likelihood model (ELM) and Toulmin's model of argumentation, we examine the effects on consumer trust of two levels of source and two levels of content factors, under two levels of product price, in a laboratory experiment with 128 subjects. Product price was predicted as a moderating factor that would influence the customer's motivation to scrutinize more closely the content of the trust-assuring arguments. The results suggest that customers are more influenced by the content of trust-assuring arguments when the price of a product is relatively high than when it is relatively low. Presumably, Internet stores employ a third party's trust-assuring arguments because customers are less likely to trust an unknown Internet store's own trust-assuring arguments. However, the results paradoxically may imply that when customers have more at stake (e.g., buying a high-price product), they do not necessarily have to rely only on an independent third-party source to form high trust beliefs about the store. When customers purchase a high-price product, they seem to form trusting beliefs by scrutinizing argument content rather than by depending on heuristic cues (e.g., an independent party's opinion) as the ELM would predict.
A trust-assuring argument refers to "a claim and its supporting statements used in an Internet store to address trust-related issues." Although trust-assuring arguments often appear in Internet stores, little research has been conducted to understand their effects on consumer trust in an Internet store. The goals of this study are (1) to investigate whether or not the provision of trust-assuring arguments on the Web site of an Internet store increase consumer trust in that Internet store and (2) to identify the most effective form of trust-assuring arguments to provide guidelines for their implementation. Toulmin's (1958) model of argumentation is proposed as a basis to identify the elements of an argument and to strengthen the effects of trust-assuring arguments on consumer trust in an Internet store. Based on Toulmin's (1958) model of argumentation, three elements of arguments that commonly appear in daily communication; namely, claim, data, and backing, are identified. Data refers to the grounds for a claim, while backing is used for providing reasons for why the data should be accepted. By combining these three elements, three forms of trust assuring arguments (claim only, claim plus data, and claim plus data and backing) are developed. The effects of these three forms of trust-assuring arguments on consumer trust in an Internet store are tested by comparing them to a no trust-assuring argument condition in a laboratory experiment with 112 participants. The results indicate (1) providing trust-assuring arguments that consist of claim plus data or claim plus data and backing increases consumers' trusting belief but displaying arguments that contain claim only does not and (2) trust-assuring arguments that include claim plus data and backing lead to the highest level of trusting belief among the three forms of arguments examined in this study. Based on the results, we argue that Toulmin's (1958) model of argumentation is an effective basis for Web site designers to develop convincing trust-assuring arguments and to improve existing trust-assuring arguments in Internet stores.