The smaller and simpler the system the easier it is to find what you want. It is pretty easy to find pertinent Cochrane systematic reviews from the the 9,000 in the Cochrane database. It is quite a bit harder to find what you want in PubMed with its 32,000,000 articles.
The larger and more complex the system the more time it will take to create an effective search.
The ideal search finds all the articles which answer a question and no more. In real life no search ever does that. Time and effort spent correlates with how close you get to the ideal.
Precision and recall are often used in information science to describe how well a search functions. You can compare them to sensitivity and specificity. A very precise search returns a small number of useful results and is likely to miss other relevant articles. A search that has high recall finds nearly everything about a topic. Much of what is found is irrelevant. A high recall search requires more time and effort to sort results. Take aways? There is a tradeoff between precision and recall in searches. There is no such thing as a perfect search. It is necessary to consult multiple sources to lower the chances of missing important papers. Examining related articles and reference lists of pertinent articles will identify additional relevant information.
One of the cornerstones of Evidence-Based Practice (EBP also called Evidence-Based Medicine or EBM) is the PICO model. PICO is a framework which helps questioners frame a clinical question.
The rest of this guide discusses methods to create effective searches for databases or search engines.
The search process is iterative. It is rare to create a good search on a new topic in your first attempt. Trial and error will lead to an improved search
When you are new to a topic, we recommend starting with Background information. In the UCSF environment this translates to books and review articles. This material provides context, is often more general, is more likely to be out of date, and provides the information you need to understand foreground information
Foreground information is more specific, more in depth, and tends to be the most current information. When you have the background information you need about your topic, it is time to consult foreground sources. In our environment this primarily means article databases.
Throughout your career you will have both background and foreground questions. More background questions at first; less as you progress in training and experience.
|Name||What is it good for||Size|
|PubMed (contains MEDLINE)||Biomedical sciences (US Nat'l Lib Med)||27 M|
|Embase||Biomedical sciences (Elsevier)||34 M|
|Web of Science||Life sciences, Social sciences (Clarivate)||35 M|
|PsycINFO||Psychology (ProQuest)||4.4 M|
|Sociological Abstracts||Sociology (ProQuest)||?? M|
|CINAHL||Nursing and allied health (EBSCO)||5.2 M|
|ERIC||Education (ProQuest)||1.2 M|
Each of the databases in the table above can be found by searching in the search box on the library home page; results will be found to the right of the page in the Database area.
There are a wealth of databases to be found in the Databases link in Popular Links on the Library Homepage.
|Name||What is it?||Tips/Tricks|
|The current mother of all search engines...||Limit by .edu or .gov domains in Advanced Search|
|GoogleScholar||Google results filtered for academic content. Mostly published articles but also papers and presentations, white papers, etc.||
Settings. Used Advanced Search. Simplify PubMed searches. Find at scholar.google.com
|Tripdatabase||An Evidence-Based Medicine (EBM) search engine. The free version is very useful. You can get some bells and whistles for $40/year.||Try the PICO search. Find at tripdatabase.com|
|SUMsearch||A somewhat idiosyncratic search engine for EBM.||There is no substitute for trying this one...find at sumsearch.org|