Common search techniques
There are several different search techniques that you can use to control how the database interprets your search query. Keep in mind that all search techniques do not work everywhere. To be sure what works in a particular database, you must look in the database's help section.
If the words you use when searching are to stand in a certain order, you can add quotation marks ("...") around them, for example around "World War II ". Then the database searches for the words as a unified concept, exactly in the order you wrote them. If you search without quotes, the database can search for each word individually. Then you will most likely get many hits that are about the World War, but not specifically World War II .
A word can have several different endings, such as nurse or nurses . To include all variants of the word in your search, you can add an asterisk (*) after the word. This is called truncation. This is called truncation. Example: teach* will return all words beginning with teach, such as teach, teaches, teacher, teachers, teaching. If you do not use truncation, you will only find results with the exact word you searched for. For example, if you search for teach you will miss any results containing the words teaching and teachers.
To combine several different keywords, you can use the Boolean operators AND, OR and NOT.
- AND is used when you want all words you search for to be included in the same article. It therefore limits the number of hits. For example, if you search using television AND movies , you will find documents where both television and movies are found somewhere in the text.
- OR is used when you want one or the other word to be included in the hits. It increases the number of hits. For example, you can use OR when you want to search for several different synonyms or spelling variations. If you search using television OR movies , the hits will contain either the word television, movies or both.
- NOT is used when you want to limit the number of hits by excluding a word. A search using television NOT movies produces hits that contain the word television , but deletes all hits where the word movies is included. However, when searching with NOT, you may miss interesting hits that contain both the word television and movies.
If you use more than one operator, you need to add parentheses to show the database how the search should be interpreted. Example: (children OR kids) AND television. The hits then contain either the words children, kids or both, along with the word television .
In some databases you can use subject headings when searching. The words in the subject headings are controlled, meaning that the word is used to describe a particular term. When you are searching with subject headings, you must use the word in the subject heading for the specific database you are using. Just select the word you want to use, otherwise you will do a regular search using free text words. Use the database help section to get more detailed information on how to search with subject headings in the database. Keep in mind that the terms in the subject headings may vary depending on which database you are using.
Field Search is an advanced search that you can use to narrow your search results. In a database, publications usually contain information about authors, title, year of publication, keywords and so on. This means that with the help of different fields you can choose whether you want to search for a specific author, title, journal title and more.
By looking in the reference lists of various publications you can get tips on new sources that you can use in your work. This is called manual search or chain search. In citation databases such as Scopus and Web of Science , you can also see who has referred to the source.
Narrow your search
In most databases you can restrict your search by filtering your hit list, for example based on publication date, language or source type. It can be good for reducing the number of hits and finding the ones that are most relevant. Another useful limitation that you can use is " Peer reviewed " or " Peer reviewed journals" . Then you should only get material that has been scientifically reviewed, but you always have to check for it yourself.
Refine your search
It is important to remember that information retrieval is a process where you have to try searching several times. You may need to change the database, change your keywords or combine them in different ways to get a good result.
Too few hits
If you get too few or incorrect hits when you search, you may need to change your keywords. It may then be helpful to use more general terms and concepts to broaden your search. You can also try truncating the keywords using an asterisk or combining synonyms with OR, so you don't miss different variations of the words. Also, make sure you've spelled the keywords correctly.
Too many hits
If you get too many hits, try using more specific words to narrow your search. You can also add keywords using AND, restrict the search with filters, or use the NOT operator to exclude hits.
Document your search
A scientific approach requires transparency and reproducibility. This means that everything you investigate should be clearly structured so that someone else can repeat or control your investigation. When writing an essay, report or other assignment, it is common for you to also report how you found the information for your assignment, therefore you should document your entire search process. Many databases have a feature called Search History. There you can see what searches and refinements you have done and save them to your computer. In addition to documenting your search results, you need to specify:
- When you did the search
- Which databases and search services you used
- Number of hits in each database
- Which keywords and search techniques you used
- Which filters you used, such as peer reviewed, language or year.
- How you have made your selection of articles