Evaluation of the User Interface for Electronic Medical Information Systems

Rebecca L. Dubowy, BA, Charlotte Bell, MD, Keith Ruskin, MD, Rene Hagenouw1, MD

Department of Anesthesiology, Yale University School of Medicine, New Haven, CT

1Erasmus University, Rotterdam, The Netherlands

 

Summary

A three-step methodology consisting of usability studies, site redesign and log file analysis was used to improve user interactivity at an anesthesiology educational web site. Average user session length increased by 27% after application of this system.

 

Introduction

GASNet, the Global Anesthesiology Server Network, was established 5 years ago by a group of anesthesiologist-computer scientists with the goal of developing Internet technology for use in medical education. As usage of the Internet has broadened to include a vast audience with a diverse range of technical expertise, accessibility and usability of the site's content has become an important aspect of ongoing site development. As it is not feasible to study the information-seeking behavior and user preferences of the entire GASNet audience, it became imperative to develop a methodology to study usability in a small targeted group that could then be applied to the larger audience.

 

Methods

A step-wise evaluation of site usability was performed using a methodology that combines a qualitative

and quantitative analysis of the user interface.

Step I: A group of 5 medical students with no prior experience with GASNet performed a series of defined tasks on the web site.  Technical errors were identified and acceptance or rejection of design features was quantified at the end of each task (usability studies).  These tasks required several different modes of information seeking including using the search engine, using the Table of Contents (TOC) and navigating from the top-level menu bar. 

Step II: Technical errors identified were corrected and areas of poor usability were redesigned.

Step III: Log file analysis (WebTrends, www.webtrends.com) was performed to quantify user activity on the web site including number of hits and user sessions, site entry and exit points and number of individual page hits.   Statistical analysis is limited to report of frequency.

 

Results

I. Qualitative usability studies indicated that a) users most commonly started navigation with the top-level menu bar; b) users preferred the TOC for navigation once its link was identified by scrolling down on the home page; c) more user errors were present when navigating with the search engine than with the TOC.

II. Changes made to the site over a 60-day period after the usability studies included moving the TOC proximally on the home page and correcting technical and design usability problems.

III. Results of log file analysis (below) indicate a consistent increase in average user session length (27%) and more frequent use of the TOC after site improvements.

 

When 

Avg# user hits/day

Avg # user sessions/day

Avg user session length

Position of

TOC *

Position of

Search *

Pre-usability

30,425

1913

11:39

6

3

60-90 days post

30,695

1884

12:25

5

3

90-120 days post

31,400

1872

14:51

4

3

*Position of TOC or search in list of most requested pages.

 

Conclusions

Research in information seeking behavior indicates that discrete sociological groups with common interests and goals seek information in a similar fashion (1). Therefore, it should be possible to project the results of a usability study performed with small populations onto a larger virtual audience (i.e. the Internet). This study indicates that usability studies on small groups can improve user interactivity with Internet-based education systems.

 

Reference

Allen TJ. Managing the Flow of Technology. The MIT Press, Cambridge, MA, 1995.