2005). In our application, this is inadequate
for many reasons: there is rarely an exact string
sentence. The “outcome”, another term from
match between system output and drugs men-
evidence-based medicine, asserts the clinical find-
tioned in CE, primarily due to synonymy (for ex-
ings of a study, and is typically found towards
the end of a MEDLINE abstract. In our case,
ample, alpha-adrenergic blocking agent and α-
blocker refer to the same class of drugs) and on-
outcome sentences state the efficacy of a drug in
tological mismatch (for example, CE might men-
treating a particular disease. Previously, we have
tion beta-agonists, while a retrieved abstract dis-
built an outcome extractor capable of identifying
such sentences in MEDLINE abstracts using su-
cusses formoterol, which is a specific represen-
tative of beta-agonists). Furthermore, while this
pervised machine learning techniques (Demner-
Fushman and Lin, 2005; Demner-Fushman and
evaluation method can tell us if the drugs proposed
by the system are “good”, it cannot measure how
Lin, 2006 in press). Evaluation on a blind held-
out test set shows high classification accuracy.
well the answer is supported by MEDLINE cita-
tions; recall that answer justification is important
5 Evaluation Methodology
for physicians.
The nugget evaluation methodology (Voorhees,
Given that our work draws from QA, IR, and sum-
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