Wongsuphasawat, K., Plaisant, C., Taieb-Maimon, M., Shneiderman, B. (October 2009)
Specifying event sequence queries is challenging even for skilled computer professionals familiar with SQL. Most graphical user interfaces for database search use a exact search approach, which is often effective, but applies an exact match criteria. We describe a new similarity-based search interface, in which users specify a query by simply placing events on a blank timeline and retrieve a similarity-ranked list of results. Behind this user interface is a new similarity measure for event sequences which the users can customize by four decision criteria, enabling them to adjust the impact of missing, extra, or swapped events or the impact of time shifts. We describe an example of use with Electronic Health Records based on our ongoing collaboration with hospital physicians. Then we report on a controlled experiment with 18 participants that compared exact search and similarity-based search features. We report on the advantages and disadvantages of each approach and conclude with recommendations for the design of a hybrid approach combining both interfaces.