Tapping trumps typing:how users enter data in an electronic student encounter log.

Handheld encounter logs that accurately record patient diagnoses could facilitate several educational tasks. Unfortunately, data entry on handheld computers is notoriously difficult, requiring either tapping buttons or entering text, for instance by typing. In most medical reference software, long lists of inputs adjust to match typed data, reducing the burden of data entry. Tapping is faster if the user can locate the correct target quickly, but designing and maintaining screens with many fixed targets is tedious, and the program grows large. We developed an Electronic Student Encounter Log, ESEL, allowing students to tap or type to record problems observed in ambulatory patients. The tapping interface comprises collections of related disease checkboxes organized in a shallow, broad tree structure, making 983 diagnoses visible with 2 taps. The typing interface mimics typical reference software, scrolling and searching a list of 1332 common problems in response to user-entered text. ESEL records the paths that students take through the program while trying to record diagnoses. Analysis of 62 students' ESEL records from ambulatory care settings demonstrates that they used the tapping interface much more often than the typing interface, and could record data more quickly by tapping than by typing. If accuracy proves to be acceptable, more robust tapping interfaces deserve wider consideration for data capture on handheld computers.