Objectives: The authors discuss the usability of an automated tool that sup
ports entry, by clinical experts, of the knowledge necessary for forming hi
gh-level concerts and patterns from raw time-oriented clinical data.
Design: Based on their previous work on the RESUME: system for forming high
-level concerts from raw time-oriented clinical data, the authors designed
a graphical knowledge acquisition (KA) tool that acquires the knowledge req
uired by RESUME. This tool was designed using Protege, a general framework
and set of tools for the construction of knowledge-based systems. The usabi
lity of the KA tool was evaluated by three expert physicians and three know
ledge engineers in three domains-the monitoring of children's growth, the c
are of patients with diabetes, and protocol-based care in oncology and in e
xperimental therapy for AIDS. The study evaluated the usability of the KA t
ool for the entry of previously elicited knowledge.
Measurements: The authors recorded the time required to understand the meth
odology and the KA tool and to enter the knowledge; they examined the subje
cts' qualitative comments; and they compared the output abstractions with b
enchmark abstractions computed from the same data and a version of the same
knowledge entered manually by RESUME: experts.
Results: Understanding RESUME required 6 to 20 hours (median, 15 to 20 hour
s); learning to use the KA tool required 2 to 6 hours (median, 3 to 4 hours
). Entry times for physicians varied by domain-2 to 20 hours for growth mon
itoring (median, 3 hours), 6 and 12 hours for diabetes care, and 5 to 60 ho
urs for protocol-based care (median, 10 hours). An increase in speed of up
to 25 times (median, 3 times) was demonstrated for all participants when th
e KA process was repeated. On their first attempt at using the tool to ente
r the knowledge, the knowledge engineers recorded entry times similar to th
ose of the expert physicians' second attempt at entering the same knowledge
. Ln all cases RESUME, using knowledge entered by means of the KA tool, gen
erated abstractions that were almost identical to those generated using the
same knowledge entered manually.
Conclusion: The authors demonstrate that the KA tool is usable and effectiv
e for expert physicians and knowledge engineers to enter clinical temporal
abstraction knowledge and that the resulting knowledge bases are as valid a
s those produced by manual entry.