Database Searching

Here we will be covering a number of search features and techniques that may be unfamiliar to most of you. Note that these search features and techniques apply to most of the databases we'll visit and explore together in this course (library catalogs, article databases, even web search engines!). So, make sure you refer to this discussion to refresh your memory as we move along in the term.

Here is an introduction to some basic search features most databases are build around:

What is Subject searching? 

As you might have noticed, a number of databases, including library catalogs, allow you to do Subject searches. Here is an example from our library catalog "see "Subject Heading" in the Quick Search window):

In a nutshell, Subject searches are searches "about" a subject, which is quite different from Keyword searching, as you will see below.

To understand how subjects searches work, you need to be aware that every item (books, articles, etc.) in a database is assigned at least one specific subject heading, sometimes also called "descriptor." This helps categorize or organize all these items in a database or library catalog.

For example, the book, College study skills: Becoming a strategic learner (2006), by Dianna Van Blerkon, is assigned the following subject headings: Study skills; Note- taking; test-taking skills, all of them referring to the content of the book.

Subject headings or descriptors, come from a list of standardized terms the databases use, and their purpose is to describe the content of the book, article, etc. What this implies is that someone actually looked at an item, determined the content of the item, and then selected one or more subject headings/descriptors to describe it.

If you know the specific subject term that matches your topic, try a subject search. You'll find out that the results you get include a list of items whose content matches your topic.

For example,

• use the COCC Library Catalog and try to find books on Native Americans.  Note that the subject heading, specific term you need to use for this subject, is  "Indians of North America." 
• After you do your subject search, go ahead and click on one of the subject headings, e.g.,  Indians Of North America Agriculture History. 
• As you look at the description of the item/book for this descriptor, you will notice that the subject field under the heading SUBJECTS contains not only the subject heading you clicked on (Indians Of North America Agriculture History), but also additional headings that describe the content of a book - see below screenshot:

  What is the use of Subject searching?

The power of Subject searching and use of standardized terms (subject headings) is that, as indicated above, it returns results whose content matches your topic. In other words, all the results you get under a subject heading will be relevant to that topic.  In addition, since there may often be many ways of saying the same thing, subject headings "control" for synonyms and other problems such as plural endings or alternative spellings. This way you don't have to worry if you have to use in your search one term over another (for example, women versus females) since the results are categorized under these standard terms.

In the example above, when you used the catalog to look for books on "Indians of North America," you did not need to perform additional searches to also look under the terms "Native Americans," "American Indians," etc.  The term "Indians of North America," which is the standardized term in the library catalog for this subject, covered it ALL!

  What if my Subject search does not work?  

Sometimes you may find out that a subject search in the catalog or database may refer you to the "right", standardized term that you should use instead.  In the example below, when you type in abuse of animals as a subject search in our library catalog, the catalog points you to the subject heading animal welfare that you need to use instead:

There may also be occasions in which you may simply attempt a Subject search to get no results!  Again, the case probably is that   you have not used the right kind of term for your topic. In this case you will need to experiment with a different term until you find the right standardized term. 

It is true, however, that trying to locate the "right" subject heading for your topic may prove to be a little tricky... In cases where subject searches fail and subject headings are not easy to find, you may want to switch to a Keyword search as described below.

A final note on Subject searches:  I call Subject searches "smart" searches because they are content-based searches. In other words, when you look at the results of a Subject search, you can be quite sure that all the items (book, articles, etc.) you retrieved are on your topic. 

   What is Keyword searching?

First a couple of definitions...

An "item record", otherwise called "bibliographic record", is what describes a book, video, etc., in a database like in the example right below. Also, in each item record you have different "fields" such as title, name of author(s), subject heading(s), etc. 

So, why is it important you understand these two terms, "item record" and "fields"?  Well, in a Keyword search you do not have to be concerned what the standardized or "right" kind of term is to look for results. A Keyword search takes your search terms the way you type them in and looks for them in all "fields" (title, name of author(s), subject heading(s), etc.) of an "item  record". 

For example, in the result below from the COCC catalog, the Keyword search terms, child and play, are highlighted in yellow in the item record of this book including the different fields where these words were identified (in this case, in the title and subject fields):

Note that a Keyword search does not care about the actual "meaning" of your terms - it just looks for the forms of the words you typed.  As a result, if you misspell a word, it will look for the misspelled word; if you type in a word in its singular (child versus children), it will probably NOT look for the plural, etc.  

  What is the advantage of Keyword searching?  

As you may be able to tell, the advantage of a Keyword search over a Subject search is that it's more flexible since you don't have to worry about using the right subject heading/descriptor for your topic. 

Keyword searching can also be great when you research a specific topic and subject headings may be too broad to describe.  For example, a Keyword search may be your best choice when you need to combine different terms to narrow down your results, such as "dairy and allergies." for which there is no specific subject heading. 

  What is the disadvantage of Keyword searching?  

On the other hand, one of the disadvantages of a Keyword search is that it may bring back a number of irrelevant materials. Since the Keyword search, as described above, looks for your terms in all different "fields" in an item record, it can pick up the term you typed in in the title, abstract, notes, or other fields. If you examine the subject field of your results, you may find out that some of these items are not at all relevant to what you are looking for!

For example, a Keyword search for "AIDS" may also pick up items about "hearing aids." In contrast, a Subject search on AIDS will give you results just on the disease.  See example below of a keyword search result taken from the COCC catalog:

Since Keyword searching tends to me so popular despite its challenges, we'll learn next about a number of techniques that improve the efficiency and effectiveness of such searches.