What makes re-finding information difficult? a study of email re-finding

Re-finding information that has been seen or accessed before is a task which can be relatively straight-forward, but often it can be extremely challenging, time-consuming and frustrating. Little is known, however, about what makes one re-finding task harder or easier than another. We performed a user study to learn about the contextual factors that influence users' perception of task difficulty in the context of re-finding email messages. 21 participants were issued re-finding tasks to perform on their own personal collections. The participants' responses to questions about the tasks combined with demographic data and collection statistics for the experimental population provide a rich basis to investigate the variables that can influence the perception of difficulty. A logistic regression model was developed to examine the relationships between variables and determine whether any factors were associated with perceived task difficulty. The model reveals strong relationships between difficulty and the time lapsed since a message was read, remembering when the sought-after email was sent, remembering other recipients of the email, the experience of the user and the user's filing strategy. We discuss what these findings mean for the design of re-finding interfaces and future re-finding research.