Eliciting Implicit Information Needs in E-Commerce Search by Using the Think-Aloud Method

In this paper, we elicit implicit information needs that arise during the process of deciding which products to purchase on e-commerce (EC) sites.We designed product purchase tasks to capture implicit information needs, and we conducted a user study to collect utterance data using a think-aloud method.By analyzing the utterances of participants during the tasks, we developed a taxonomy comprising five categories where people express preferences for products and 11 categories where people want to understand products.Our taxonomy includes implicit information needs that have not been captured in existing EC-related taxonomies (e.g., Preference for Subjective Attributes and Understanding Product Differences).We revealed the characteristics of each category of information need in terms of timing during the tasks: e.g., the information need of Understanding Product Range occurred very frequently in the early stage of a task.We also revealed the occurrence frequencies for different task types: e.g., the information needs of Preference for Objective Attributes, Understanding Product Range, and Understanding Terminology had a higher occurrence when purchasing products less frequently and at a higher cost than when purchasing products frequently at a relatively low cost.Our taxonomy could be used to further improve users' purchasing processes on EC sites.