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Preparing for your dissertation/project: Advanced searching and tools

Preparing for your dissertation/project

Also see Finding Information on the Internet

Advanced Database Features

Many databases, particularly large bibliographic databases that you would use to find as many articles published on your topic of research as possible,  have advanced features to help you to optimise your searching. Take a look at the document above for details.

Don't forget that your Academic Liaison Librarian for your course can help you to find and use these features.

Useful videos on database searching:






Boolean Searching

Venn diagram of Boolean AND operator

AND is usually implied. It tells a database to find all of your search words.

Google and most databases automatically search as if you’d typed AND between them.

This means that both words may appear individually in records, not necessarily near or next to each other.

If you want to search for an exact phrase, see the section on phrase searching.

Venn diagram of Boolean OR operator

OR is used to connect similar concepts (synonyms) and tells a database to find any or all of your search words.

Horror OR thriller would find records that mention at least one of these words.

Venn diagram of Boolean NOT operator

NOT can be used to exclude a word. For instance: horror NOT ghosts.

This would find all items that mention horror, but then take out the ones that also mention ghosts.

Parentheses (brackets) in Boolean searches

Some databases will give you separate search boxes. For instance, databases hosted on the EBSCOhost platform

This allows you to search without brackets. All words linked with OR for one aspect of a search go in the same box. Here's an example:


In a database where you are offered only one search box, if you are using both AND and OR in the same search, you will need to use brackets.

If you were to express a search in the same way as below, your results would include records that mention film and horror, and then records that mention thriller not necessarily in combination with film: 

AND and OR search without brackets in a single search box  


However, using brackets, as shown below, ensures that your results are comprised of records that mention film with either horror or thriller: 

AND and OR search with brackets in a single search box  

Phrase searching

Phrase searching works in Google and most databases, but you may find that a database has a phrase index that it searches instead of item titles and abstracts. If this is the case, and your phrase does not appear in the phrase index, then the search will not work particularly well. One database that definitely does this is PubMed.

If you definitely want to find records where your search words appear next to each other as a phrase, simply enclose them in speech marks:

Words enclosed in quotation marks to denote a phrase search "horror film"

Truncation and wildcards

It is possible to use a symbol to denote extra or unknown characters, though it's generally not necessary to do so for plural versions of words or for American and British spellings, as databases usually automatically search for these. Which symbols are used can vary, so always check the 'help' or 'search tips' section of the database you are using, or Google if you're searching using Google.

To truncate a word and search for all possible endings, usually an asterisk (*) is used. For example, if you wanted to find records mentioning psychology, psychological, psychologist or psychologists, you could type:

Truncated word with asterisk at the end to search for all endings of the word - psycholog*

Proximity searching

Databases will vary on terminology used (what you should type in or select). For instance, the IEEE Xplore database calls the 'Within' operator 'ONEAR' and has it's own 'command search' within 'advanced search' for you to do this kind of searching. The maximum number of words that you can specify between your search words can also vary, anywhere between 10 and approximately 255. Whether you type the letter (N) or the whole word (NEAR) also varies. Please check the help or search tips facility in any database before attempting this type of search, but here are some basic examples:
Search using the NEAR operator to specify 2 words within 5 words of each other in any order
The NEAR (N) Boolean operator can be used to specify that two or more search words appear within a specified number of words of each other, and in any order. Using a phrase search, such as "personality theories" is too limiting and would not find phrases such as "theories of personality", whereas this technique would find any phrase containing personality and theories in any order within 5 words of each other.
Search using the WITHIN operator to specify that 2 search words appear within 5 words of each other in this exact order
The WITHIN (W) Boolean operator can be used to specify that two or more search words appear within a specified number of words of each other, but only in the order in which they were typed by you. This technique would find phrases containing personality and theories in that order, not theories and personality.