Using databases seems intuitive. Google has made searching for information easier than ever. However, databases used for scholarly research aren't all built like Google, and special skills need to be developed in order to get the most out of them. Below, you'll find some strategies to help you in your research. Don't forget to reach out to library staff for video passwords!
Sometimes your first search terms don't produce the results you were hoping for. In these cases, you can use advanced search options to narrow down, expand, or modify search results.
Watch the video below to learn more about controlled vocabulary, Boolean operators, filters, and snowballing, or check out the information further down the page to read about it.
Boolean operators are how we modify searches. For example, let's say you are searching for acupuncture or herbal treatments for amenorrhea.
Use Boolean operators (AND, OR, NOT) to combine or exclude search terms:
If you wanted to find information about acupuncture OR herbs in the treatment of amenorrhea, you would use parenthesis to set your search phrase. Look at this search phrase:
Amenorrhea AND Acupuncture OR Herbs
Boolean formulas read like a mathematical formulas, from left to right. So this search phrase would retrieve Amenorrhea AND Acupuncture. OR it would just search Herbs. In order to remedy this, you should use parenthesis to define your search parameters:
Amenorrhea AND (Acupuncture OR Herbs)
You can use the asterisk symbol to create truncation and wildcards, which will allow you to account for variations in spelling.
Filters allow you to limit the results you get in a database. You might think having a lot of results come up in your search is great, but having too many results can be overwhelming. What would you do if your search came up with over 2,000 hits? Would you have the time, patience, and attention span to scan each article to see if it is worth your time? Your answer is probably no. And that is fine -- because that is why filters were created. Filters allow you to narrow down your search results to just those articles that are relevant to your search. There are many kinds of limits -- you can limit by type of research (RCT, systematic review, case study, etc.), by year published, by subject heading -- some databases even let you limit by the subject species (such as tests involving rats) or by gender or age (only studies done on adolescent females).
When you search multiple databases at once in EBSCO, each of those databases has their own set of individualized filters. The problem with searching in multiple databases that use different filters is that if you turn on a filter, you may be limiting perfectly good results from databases that don't use those filters.
To conduct a completely comprehensive literature review, you should search each database independently, which will allow you to take full advantage of the limits set up for that database.
Databases use a specific language; just like in real-life, if you don't know the language, it can be difficult to find what you are looking for. If you are using normal human conversational language to find research, but the articles in a database are organized using medical terminology, anything you do find will be only a fraction of the story.
You can use the database’s thesaurus to find subject terms. Different databases may use different subject headings, so it is a good idea to check what terms the database actually uses. MEDLINE uses MeSH (Medical Subject Headings), which is what the OCOM Library also uses to organize materials.
The video below provides some more information on how to use keyword vocabulary and subject terms
Snowballing is when you find a resource and scour the bibliography for related references. This will lead you to other resources, which in turn may lead you to even more references. This is a great way to find citations that might not be indexed in large databases or grey literature (see the next section for more information on grey literature). Sometimes all it takes is one really good journal article to get you snowballing. You might hear other terms for this as well, such as "hand searching," but snowballing is my favorite because it is such a great metaphor for this activity.
When you find references in a bibliography, you are looking at older research -- stuff that was written that influenced the newer article or book. But using a Google Scholar function, you can flip this and search for newer research. If you've found a good article, you can try searching for it in Google Scholar. When you find the article, there will be a link that says, "Cited by ___," with the number of found citations. If you click on the link, you will see all the newer citations that have referenced this article.
Grey literature is literature that is not published by conventional means. Some examples of grey literature include conference proceedings, government documents, wikis and blogs, theses, and clinical trial registeries.
Researchers and publishers often do not publish results from studies that show negative or null results. This is not just a problem of publishers refusing to publish reports, but is often a self-imposed censorship by researchers who do not wish to showcase their unsuccessful trials. The problem with this is that journal publications are how researchers communicate findings to one another. You won't know that a type of therapy is not successful if people don't publish those results.
Grey literature is important because it fills this evidence gap. By searching for information that is not published, you can find information that you wouldn't necessarily find in commercial publications due to publication bias.
You can read more about searching for Grey Literature by checking out UBC's Guide.