Now that you understand the underlying construction of a database, let's look at the organization of a simple database.

Consider a database that lists all books a library owns -- the library catalog. How would you organize a spreadsheet that listed every book in the library?

Generally, the information is organized so that each book gets a row in your spreadsheet. But remember, there are many columns in the spreadsheet, so our single book (row) can have several columns worth of information stored in individual cells. What type of information? Well, what type of information would you generally want to know about any book?

Title
Author
Publisher
Date of Publication

Yes, all of those would be good information to have and great tools to use when searching for a book. If you knew the author's name, you could search down the column for "Authors" and ask the database to match the name you're looking to find. You would type in the author's last name, a comma and perhaps the first name. If the library owned more than one book written by your author, all books would be listed. If they did not own any books written by your author, your results would be zero. Simple enough.

Likewise, if you were searching for a title, you'd direct the database to search down the column where all titles are listed and find matches for that title.

But what if you don't know either the title of a book or the author of a book, but you know you want to find a book about something like butterflies?

The database has another column that allows you to search based on selected index words. Years ago most databases used a "controlled vocabulary" (a finite list of words that could be associated with items stored in the database). Today you don't have to look up words that you are allowed to use. Instead of researching words available in a controlled vocabulary, you need to consider what word YOU would associate with the type of information you want to locate.

In this example, we would probably want to try using the simple index word, "butterflies". Or perhaps, the singular form -- "butterfly". Remember, the database only matches the characters you type. It doesn't look for alternative spellings or for plural (or singular) forms of any word. If you want to use both singular and plural form, you must enter those as separate index terms to make sure your search covers both. This is especially true where the plural of a word is very different from the singular (child / children).

Now you've considered your options and you know what index word you wish to use; where do you find the "index word" column on the database search page? Usually the default search box in a database will function as the index word search column. It could also be called any number of other names, such as keyword, words, words anywhere, anywhere, and -- sometimes -- subject.

Be careful using a column in a library-related database that is called "subject" as this sometimes refers to "Library of Congress Subject Headings" rather than topics or keywords. The entire list of Subject Headings are found in a multi-volume book published by the Library of Congress and available at the Reference Desk of your library. The Subject Headings are actually a string of very specific words rather than one index word. It requires you look up the entry and use the exact string along with all associated punctuation. It is NOT something you can do intuitively. However, if while conducting your search in a library catalog you find an entry for a book that is exactly what you're looking for, check the Subject Heading listing (usually a clickable link) within that entry and try doing the same search. It will often provide you with an unexpected route to the subject material you are interested in locating. Here are a few examples of what a LC Subject Heading (search) looks like:

Jefferson, Thomas, 1743-1826.

Presidents -- United States -- History.

Executive power -- United States -- History.

But again, the column in a database labeled "subject" is one you need to inspect carefully prior to using. Subject Headings, as mentioned above, are not intuitive and used incorrectly can cause no end of frustration. Understanding what you can achieve by using these links can conversely make your life as a researcher much easier. It's all in knowing what tools can accomplish and which tools to use to achieve a desired result.

To summarize, then:

When you search for a book (or journal article) and do not know the title or the author, a database will allow you to search by index words.
The search column for index words is usually the default search box.
You often have the option of changing which column you search, usually via use of a drop-down box to select another column.
Once you have selected the search column you feel appropriate, remember to keep your search terms appropriate to that column.
When searching for index terms, the database searches very quickly down the column for any words that match your keyboard input.
The computer does not understand the meaning of search words, it merely matches characters you input from keyboard or touchscreen.
Whenever the computer finds a match for your search term, it pulls the entire row of information and places it into a new spreadsheet.
When the database has completed it's search, it will display the results in the new spreadsheet for you to view.

We have now progressed

from wondering what a database is
to understanding how data is organized inside a database
to understanding how we (as researchers) can manipulate the database to search for
the type of data we want (titles, authors, index words) to get a list of books or journal articles that match our search request.

Suddenly it seems much easier than it did just a short while ago!

But there are still more things that you can do to control how and what the database does while searching that will help you narrow your focus or expand your search terms. This is important to have as a tool because if all we could do was ask the database to give us everything it had about "cat," we would likely have not just hundreds of results in our list of titles the database found for us, but hundreds of thousands of items!

While having bunches and bunches of information sounds wonderful, it causes another -- and very serious -- problem for us as researchers. The time factor comes into play. It takes time to read ten titles. Maybe not much, but it does. And if we want to open the abstract and read a little more about what each title contains in it's pages, that takes even more time. How much time would it take to quickly read and review 27,000 titles? Or 227,000 titles?

Time is a major factor. Too many results ("information overload") is a serious problem. How would we know which of these 27,000 titles would be the best one for our current needs if we didn't read each one individually. Yikes, indeed!

We need a better way to organize our search.

The good news is that there IS a way to help us focus and narrow our search to retrieve a smaller, more concise number of items from our search. Or expand our search. Or even tell the database to eliminate some aspect if it appears in the results list.

What is it that helps us do all these wonderful things that helps us save time and locate specifically items that match our needs?

Boolean Operators!