The use of keywords, phrases and subject headings are the most effective ways of searching for information on any library catalogue, database or Internet site.
Searching by keyword is the easiest way to begin your search.
In keyword searching, you would use the terms you identified from your research topic. Using a single keyword can produce thousands of hits, many of which may be irrelevant or too broad. The more keywords you enter the more focused your search results will be and use Boolean Operators to connect these keywords effectively.
What is a Boolean Operator?
Boolean or Search Operators help define the relationship between keywords or groups of keywords. By making use of the Boolean Operators
AND, OR and NOT, you will be able to narrow or broaden your search, and eliminate irrelevant hits.
Boolean Operators: the use of AND, OR and NOT
AND searches for results which only contain all the keywords linked by AND, for example social media AND behaviour. This is the most common operator and is usually the default Boolean Operator in most search engines and databases, i.e. when performing a search and you do not specify an operator, AND will be inserted automatically.
OR searches for results which contain any of the keywords separated by OR, for example social media OR social network OR social networking OR Facebook.
NOT exclude the keyword that appears after operator NOT from your search results, for example social media NOT twitter.
Now that the core keywords are identified and the different Boolean Operators are known, we can start combining the keywords with the relevant Boolean Operator(s).
Let's use our example again – Investigating social media behaviour in South Africa
(social media OR social networking OR social networks OR Facebook)
(behaviour OR behavior )
(South Africa OR Africa )
This is a much more focused search strategy and will retrieve more relevant information.
It can happen that the results you retrieve include keywords that you are not interested in. Should you wish to exclude these publications you can make use of the operator NOT.
(social media OR social networking OR Facebook) AND (behaviour OR behavior) AND ( South Africa OR Africa) NOT (Twitter).
Thus, this search is limited by the use of NOT to find material that focuses only on social media. social networking and Facebook and it will exclude material containing the word ‘Twitter'.
PARENTHESES (ROUND BRACKETS)
When your search strategy becomes very complex, double round brackets can be used to group all the concepts that belong together.
( ) are used to group together keywords that are equivalent to each other in meaning. This instructs the search software of the database the order in which to search the groups of keywords, e.g. (social media OR social networks OR social networking OR Facebook) AND (behaviour OR behavior) AND (South Africa OR Africa) NOT Twitter
Note that the round brackets do not embrace the concept that must be excluded, namely, Twitter.
The word network is the stem of the word and therefore the asterisk is added to the end of the word (social network*) to ensure that the variant endings of the word stem are retrieved. Publications containing the word network or networks or networked or networking will be retrieved.
The search strategy uses the truncation symbol (e.g. the asterisk) to widen the net of the search to include variant endings.
PHRASE SEARCHING, PROXIMITY and ADJACENCY OPERATORS
A phrase search is a very useful search option as it allows you to find a short or long string of words in exactly the order in which you wish to find them. In other words, a phrase is usually a group of words which can express a concept when used together.
Most databases allow phrase searching and the must common technique is to place double inverted commas around the words that you want to search as a concept, for example "South Africa". Remember that not all databases support the same commands and it is therefore important to consult the database's help link before you start searching.
The proximity or adjacency operators will differ from database to database, so consult the help link of the databases.
Most proximity operators consist of a letter () and a number (to specify the distance or the number of words, e.g. 4 words between keywords). The proximity operator is placed between the keywords which are being searched.
Let's add a proximity operator to our search example: Investigating social media behaviour in South Africa
"social media" N4 behaviour
Subject headings describe the content of a document in a formal, structured and succinct way, and the same subject heading will be applied consistently to all documents containing similar content. In other words, subject headings use fixed and controlled language and are allocated by professional cataloguers and indexers. Subject headings offer broader, narrower and related terms to the searcher.
Subject headings can be found within certain subject databases or may be found in the well-known list of subject headings called the Library of Congress Subject Headings (LCSH). The LCSH is used in the Unisa Library Catalogue to describe the content of the Library’s four million books. Note that the Library Catalogue conforms to the American spelling and terminology used by the LCSH.
Be aware that almost every database approaches subject headings differently and that there some databases that don't allocate subject headings to their records. Words that databases use to indicate the use of subject headings can be thesaurus, subjects), topic(s), descriptor(s), terms and so forth.
More than one subject heading may be allocated to the same publication or unpublished document.
But what are the benefits of using subject headings?
They help to gather a comprehensive set of search results that are more likely to be relevant.
It is recommended that in order to get the best results, you should do both keyword and subject heading searches which complement each other.
The references in a database describe the original publications in terms of the bibliographic information, and each bibliographic element is assigned to its own field, for example, the author field, title field, abstract field, subject heading field, and so forth.
The use of field limiters allows you to focus your search or to search for very specific things, for example, all the articles written by a certain author.
A search that uses subject headings will be limited to the field of the subject heading (although it is possible to combine different fields in one search strategy). This differs, then, from the keyword search which searches across several fields in a reference (for example author, title, subject heading, and abstract fields).
LIMIT YOUR SEARCH RESULTS
Once you are happy with the relevance of your search results you can start to further reduce the number of your search results with limits that are database specific, such as:
The use of these limiters will depend on the scope of your research topic e.g historical period.