This study attempted to use semantic relations expressed in text, in partic
ular cause-effect relations, to improve information retrieval effectiveness
. The study investigated whether the information obtained by matching cause
-effect relations expressed in documents with the cause-effect relations ex
pressed in users queries can be used to improve document retrieval results.
in comparison to using just keyword matching without considering relations
.
An automatic method for identifying and extracting cause-effect information
in Wall Street Journal text was developed. Causal relation matching was fo
und to yield a small but significant improvement in retrieval results when
the weights used for combining the scores from different types of matching
were customized for each query. Causal relation matching did not perform be
tter than word proximity matching (i.e. matching pairs of causally related
words in the query with pairs of words that co-occur within document senten
ces), but the best results were obtained when causal relation matching was
combined with word proximity matching. The best kind of causal relation mat
ching was found to be one in which one member of the causal relation (eithe
r the cause or the effect) was represented as a wildcard that could match w
ith any word. (C) 2000 Elsevier Science Ltd. All rights reserved.