Library OneSearch (EBSCO Discovery Service)

A guide to use and best practices for TWU's discovery tool.

The Concept of "Filters" or "Limiters"

Library OneSearch is set up to enable keyword searching initially, but there are many filters, also called limiters, available on the results page.  A "filter" is a tool that narrows down a large number of results to something more manageable.  We know that OneSearch often brings up thousands of citations.  This is a problem because:

1. No one wants to go through thousands of results.
2. While the OneSearch engine ranks the results by relevance, this is based on a computer algorithm that may or may not get it right.  So the first page of results may not contain all of the best results.
3. Large result sets tend to be broadly focused. Filters allow you narrow your focus, which is almost always a good thing.

Types of Filters/Limiters Available



Some Alternatives for Subject Searching

This Prezi presentation will show you two alternatives for using subject headings for searching. Open it to full screen. Navigation arrows are at the bottom:

Limiters in Practice

Here is an example to show the value of limiters.  We Search Everything to search on "climate change" AND "polar bears"



With 2,747 results, we have a problem. How can we reduce the number without eliminating useful resources?



Let's first limit to scholarly articles. That eliminates books but will likely give us more current resources. Go to the left column:



Subjects focus on what the article is actually about, and thus narrow the focus. Choose the following two subject limiters, one at a time. The screen will refresh each time you click on a box:



Since our result list is still quite large, we can choose between one of two other possible subjects.  In this case, let's choose "sea ice."



We now have only 156 articles.  Note that all our limiters are listed on the left.  To turn any one of them off, click the x to the right of it.