Tips on researching
When using an index or abstract
to look for articles on a particular subject, always check to see if it
has a controlled vocabulary or thesaurus indicating what
subject words are recognized and used by that index. For example, consulting
the controlled vocabulary will clarify whether one should look up the
word "extinct," or "extinction," or "extinctions," or "animal extinctions,"
or "plant extinctions," etc.
Zoological Record offers
an entire volume called the Zoological Record Search Guide, which
is a guide to the controlled vocabulary used by that index. This guide
indicates that the word "extinction" is the recognized subject word that
you should use when searching for information on this topic.
If the index does not have a controlled
vocabulary or thesaurus, or if one is searching for books in a library's
online catalog, one can usually assume that the recognized subject headings
will be those used by Library of Congress, and found in Library of
Congress Subject Headings. The following subject headings are used
by the Library of Congress for the topic of extinction:
- Extinct animals
- Extinct amphibians
- Extinct birds
- Extinct fishes
- Extinct insects
- Extinct mammals
- Extinct plants
- Extinction (Biology)
- QE721.2.E97 (Paleontology)
- QH78 (Natural history)
When searching in an electronic
database, non-controlled subject terms can be used as well as those that
are part of the controlled vocabulary. Most databases also allow words
to be truncated in order to quickly search for all possible variations.
Terms can also be combined to refine the search strategy further.
Different databases have different symbols that represent word truncation,
some use an asterisk, some use a question mark, etc. The chances of
retrieving all possible relevant references may increase by utilizing
truncation. For example, searching "extinct*" will retrieve any references
containing the word "extinct," "extinction," or "extinctions."
Truncation should be used with
care as some words can have different endings that change their meaning.
For example, if one wanted to find information on insects and the search
term "insect*" was used to pick up references containing both singular
and plural forms of the word, one would also find that references containing
the word "insectivore" or "insecticide" would also be retrieved. Some
database offer features to help you avoid a situation like this, but
if these features are not available, you can always combine the singular
and plural form of the word with an "or" (see below).
The likelihood of picking up all possible relevant references is increased
if the search query is as broad as possible and includes all possible
words (synonyms) that are likely to be used by an author discussing
the topic. For example, when looking for information on extinction,
one might try using additional truncated words such as "exterminat*."
Searching for the word "rediscover*" may help locate articles about
species that were once thought to be extinct.
Searching in electronic databases also allows one to combine terms using
"or," and "and" to refine the search strategy, as in this search entry:
"(extinct* or rediscover*) and mammal*"
If one is searching for information
on recent extinctions, then searching for the word "extinct*" is likely
to pick up numerous articles about dinosaurs and other less recent extinctions.
Sometimes one can stipulate topics that one is not searching
for, as in the following two search entries: "extinct* not dinosaurs"
or "extinct* not (jurassic or cretaceous or ...etc.)."