Portrait of Tao Zhang

Tao Zhang

February 2014 · Purdue · research

Assessing the user experience of e-books

This is a comprehensive assessment of e-book user experience (search and information seeking) from transaction logs, e-book usage data, and user tests.

Background

E-books have emerged as a new format of scholarly resources in academic libraries. Understanding how users search for and retrieve information from e-books is critical for libraries that want to assess their impact and develop a user-centered strategy for improving e-book collections.

Research goals

  • Explore how users search for e-books in the library’s discovery tool.
  • Understand how users use e-books.
  • Understand how users find information in e-books.

Search log analysis

The log analysis measured the initial query distribution among the tabs of the discovery tool interface, query length and facet (filter) selection, as well as the number of queries and actions in search sessions.

Initial query distribution

Most searches started from the default “Search All” tab.

Distribution of initial search queries across discovery tool tabs

Query length

Book search queries were slightly shorter compared to the queries submitted in the “Search All” tab.

Comparison of query lengths for e-book searches and Search All queries

Facet usage

Searches with just one facet applied were the most common search sessions. Publication Date, Peer Review, and Subject were the top 3 facets in all search sessions.

Chart showing common single-facet usage in search sessions
Chart showing which facets were used most often in search sessions

Queries and actions in search sessions

Book searches tended to be shorter but with more actions than searches submitted in the “Search All” tab.

Comparison of query and action counts in search sessions

E-book usage log analysis

We collected EBL e-book usage logs from January to November 2014. The logs contained 29,495 individual reading sessions. The data fields included date and time, user ID, e-book title and ID, publisher, subject category, and pages browsed.

Reading session duration

Sixty-nine percent of reading sessions lasted less than 10 minutes, and 92% lasted less than 30 minutes. A total of 2,261 sessions, or 8%, included a download action.

Distribution of e-book reading session durations

Pages browsed

80% of sessions involved no more than 30 pages browsed by users.

Distribution of pages browsed during e-book reading sessions

I created a Tableau visualization of the page numbers browsed by users across e-books and grouped by publishers and subjects.

Visualization of pages browsed across e-books by publisher and subject

In summary, e-books were not typically read from beginning to end. Most reading sessions were short and involved a relatively small number of pages. In the library context, users mainly used e-books to find specific information or sections rather than read linearly.

User test

I conducted user tests with 12 participants (faculty, undergraduate and graduate students) of different experience levels. The test tasks included both exploratory search and information finding tasks.

The search tasks showed similar user behavior patterns as the search log analysis. Participants started from the default “Search All” tab. They did simple keyword search and browsed the first page of results. Participants’ difficulties were:

  • scan large number of results.
  • identify material type (e-book).
  • identify format (online access).
  • determine relevance from only book title, author, and publication year from the search results list.

For the information finding tasks, participants tended to interact with e-books as if they were websites. They relied on the in-book search which was actually inferior to web search engines. Participants expected to see keyword highlights and cross-references when clicking on highlighted keywords.

Overall, current e-books are designed for linear reading rather than information finding. As more e-books are adopted in academia, future e-books should offer flexible page views, better full-text search, more interactive navigation features, and fewer restrictions on copying, annotation, printing, and downloading.

Publications