Did your search result in too many or too few hits? By using different search techniques, you can improve your searches considerably. Some basic techniques that will work in most databases are described below.
A database search is a match between your search words and existing words in the database. When you enter one or several search words, the database will tell you if these words can be found in the database. Most search tools automatically imply AND between each word entered. If you enter two words, you will only get the results that include both words together in the same document. There are search services that automatically search for related terms and synonyms. Searches of this kind will yield a greater amount of hits.
Illustration of matching using two terms.
What happens when you execute the search in the example above, is that you ask the database to return documents where the words politics AND democracy are included - and no other documents. Had the search been executed using only the word politics, the upper left document would have been returned by the database too.
In many databases you can also use OR between the search words. Applying this to the example below, we would obtain documents that either include the terms bribes OR corruption. The operator OR is used when you want to increase the number of hits or search for several synonymous words.
Illustration of search with the OR operator.
Besides choosing which words to search for, you also need to think about the form in which you write them. For instance, if you want to find publications about democratisation studies, you might also be interested in publications with a different spelling of the word such as democratization (American English) or other endings of the word such as democracies (plural form) or democratic (adjective form). Instead of having to do several separate searches, you can use what is known as truncation. Enter the stem of the word and a truncation character, often an asterisk, like democra*, and you will retrieve all publications wherein the truncated word stem occurs, irrespective of ending.
Illustration of search with truncation.
In many databases the truncation character can also be used at the beginning or in the middle of a word. When it is used in the middle of the word, it is usually called a wildcard.
The most common truncation character is the asterisk (*), but other characters might occur, such as the question mark (?). Sometimes, different characters are used depending on whether they are used in the middle or at the end of a word. Read the search help text of the database you are currently searching in to see which rules apply.
It might be good to know that GoogleScholar uses a form of automatic truncation. A search might retrieve hits on other variants of the word used in your search. However in the library's article databases, you usually have to truncate words in order to retrieve all variants.
By putting two or more words within quotation marks, you will only retrieve documents wherein those words are in exactly that order. This technique works in most databases and search engines. Example: "third world".
Which search words you choose is crucial for a search, but you should also be aware of what kind of information you are searching in. Are you searching within the entire text of a document or only among titles, authors or other metadata describing the documents?
Searching within the entire text of documents is usually called free text search, or full text search. When you search within the entire text, you can use specified words that occur in the text.
However, if you only search using the metadata that describes the document, you cannot be as specific.
In most databases there are advanced search options where you can specify in which field you want to limit your search to. In the example below, you will only retrieve documents where the word democracy occurs in titles.
In some cases, you need to limit the number of hits your search yields. This is often the case when a database is of a general and multidisciplinary character and covers many different subject areas and publication types, resulting in lots of hits with varying relevance.
In contrast to metadata searching, setting these limits is something you do after the initial search. In the interfaces of today's databases, you will usually be offered a set of delimiters that you can use to limit your search.
For example, if you limit by publication type, you can choose to search only for journals or dissertations.
For example, when limiting your search by publication date, you can find material that has only been publish within the latest three years.
In some cases you can choose among a number of subject areas as listed by the database.
Pay attention to how search results are presented. Search lists are often sorted by publication date or relevancy. Relevancy means that the database automatically determines which documents are relevant based on your search criteria. Often you can rearrange the search results based on relevance, publication date or number of citations.