Date of Award

May 2014

Degree Type


Degree Name

Doctor of Philosophy (PhD)


Information Science and Technology


Elizabeth D. Liddy

Second Advisor

Howard R. Turtle


cues, query reformulation, search engines, user study

Subject Categories

Social and Behavioral Sciences


Given the growing volume of information that surrounds us, search, and particularly web search, is now a fundamental part of how people perceive and experience the world. Understanding how searchers interact with search engines is thus an important topic both for designers of information retrieval systems and educators working in the area of digital literacy. Reaching such understanding, however, with the more established, system-centric, approaches in information retrieval (IR) is limited. While inherently iterative nature of the search process is generally acknowledged in the field of IR, research on query reformulation is typically limited to dealing with the "what" or the "how" of the query reformulation process. Drawing a complete picture of searchers' behavior is thus incomplete without addressing the "why" of query reformulation, including what pieces of information, or cues, trigger the reformulation process. Unpacking that aspect of the searchers' behavior requires a more user-centric approach.

The overall goal of this study is to advance understanding of the reformulation process and the cues that influence it. It was driven by two broad questions about the use of cues (on the search engine result pages or the full web pages) in the searchers' decisions regarding query reformulation and the effects of that use on search effectiveness. The study draws on data collected in a lab setting from a sample of students who performed a series of search tasks and then went through a process of stimulated recall focused on their query reformulations. Both, query reformulations recorded during the search tasks and cues elicited during the stimulated recall exercise, were coded and then modeled using the mixed effects method. The final models capture the relationships between cues and query reformulation strategies as well as cues and search effectiveness; in both cases some relationships are moderated by search expertise and domain knowledge.

The results demonstrate that searchers systematically elicit and use cues with regard to query reformulation. Some of these relationships are independent from search expertise and domain knowledge, while others manifest themselves differently at different levels of search expertise and domain knowledge. Similarly, due to the fact that the majority of the reformulations in this study indicated a failure of the preceding query, mixed results were achieved with identifying relationships between the use of cues and search effectiveness. As a whole, this work offers two contributions to the field of user-centered information retrieval. First, it reaffirms some of the earlier conceptual work about the role of cues in search behavior, and then expands on it by proposing specific relationships between cues and reformulations. Second, it highlights potential design considerations in creating search engine results pages and query term suggestions, as well as and training suggestion for educators working on digital literacy.


Open Access