Evidence-Based Practice for Nurses

(Ben Green) #1

that were first published about the topic. Forward searching strategies are made
possible by electronic databases. For example, the nurse enters information for a
single article and uses a hyperlink option “times cited in this database.” This link
connects to other documents that have cited that article since its publication.


Hints for Searching Print Indexes


Because of the convenience of electronic resources, most individuals are
unfamiliar with print indexes. Typically, print indexes are used to search for
older literature that has not been indexed in electronic databases. Therefore,
perhaps the best strategy when using print indexes is to ask a librarian for help.
Librarians are familiar with the sources and know which sources will be most
useful. Because older print resources are primarily organized by time, usually
in spans of a year or two, knowing the years to search can help immensely.
Keeping in mind that search terms change over time is also important when
using print indexes. For example, whereas “patient education” is the correct
subject term today, if searching records created before 1988, the correct term
is “health education, information services.”


Hints for Searching Electronic Databases


Parameters of recall and precision provide conceptual baselines for refining
search strategies in electronic databases. The successful integration of these
parameters results in retrieved records that more closely match the desired
focus and number of sources.


Recall describes the broad “catch” of retrieved records. Those records, usu-
ally high in number, display a wide range of what has been classified as related
records. Recall is a strategy best used when the information being sought is
uniquely detailed, a new topic or procedure, or has not been widely written
about in the literature. Gathering a large number of records ensures that the
information needed is somewhere within them, even though many of the
records retrieved will not be relevant.


Precision is a search strategy that narrows the parameters of the search.
When a search term displays a precise retrieval, the records are usually smaller
in number but more closely matched to the entered search terms. This search
strategy is best when the information being sought has been written about in
a number of authoritative sources by a number of knowledgeable people. The
search can be narrowed without undue concern about the loss of some relevant
records because it is likely that the search contained needed information in
the retrieved records.


An effective technique, especially for novices whose skills are not yet finely
tuned, is to combine these search strategies. Beginning with a recall strategy


KEY TERMS
recall: A strategy
used to search
for the number of
records retrieved
with a keyword; the
broad “catch” of
retrieved records
precision: A
search strategy
that narrows the
parameters of the
search

4.4 How to Search for Evidence 111
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