Search Queries in Library Databases.
In the last video we showed you how to analyze a topic. In this video, you will learn to use the results of that analysis in an actual search. To search library databases successfully, you must be able
This video will show you how.
The first important technique enables you to search for a phrase. Remember that, when we search in library databases, we are searching for words, not topics. Most search engines are completely literal when interpreting a query, and simply match the words entered with words that appear in the documents being searched. When a query comprises more than one word, search engines usually treat the query as a set of discrete words. For example, if I search this database [Proquest Historical Newspapers] for James Earl Ray, the search engine sees three words,
not the phrase James Earl Ray, which is what I intended. The search engine retrieved articles that contained all three of these words, regardless of where in the article the words appeared. In this database, there were over 7,000 such articles, and most have nothing to do with James Earl Ray, the man who assassinated Martin Luther King Jr. Here are two examples. While all three of my search terms appear in these articles, they do not appear as a phrase.
If I want the search engine to treat these three words as a single phrase, then I have to tell it to do so. In most search engines, I indicate that multiple words are to be treated as a single phrase by enclosing the phrase in quotation marks. Even Google functions in this way.
If I try this search again, using quotation marks around my phrase, then I will retrieve a set of articles closer to what I was hoping to find. Searching for a phrase is the first of the 3 basic search techniques you will need to search library databases.
The second important technique enables you to search for variant forms of a word with a single query. Because databases are completely literal, I have to search for every form of my search term that could retrieve relevant articles. For example, if the word immigration is likely to appear in articles on my topic, then it's likely that the words
might also. If I want to retrieve all relevant documents, then I need to search for all forms of the word, not just the form that first occurs to me when I think of my topic. Most search engines do not understand that words like immigrant and immigration are semantically related. To search different forms of a word with a single query, I use a search technique called truncation.
Truncation is the technique of using a single query to retrieve all words that begin with a common stem. Let's look at that list again. These words all share a common stem. You truncate a search term by entering the common stem, followed by the search engine's truncation symbol. The most common truncation symbol is an asterisk [*]. So, in this example, instead of searching for all six of these terms separately, I would simply enter the stem "i", "m", "m", "i", "g", "r", "a", followed by the truncation symbol, an asterisk.
Let's try this example in a real database. If I’m looking for photographs that document Immigration to North America in the First Decade of the 20th century, I could search in the database ArtStor for "immigration", which returns 30 photos, or "immigrant", which returns 11 photos, but if I use truncation, I retrieve 121 photos1. Failing to truncate my search term would have meant missing most of the relevant documents in this database. Truncation is the second of the 3 basic search techniques you will need to search library databases.
The third important technique enables you to combine multiple search terms into a single query. In the previous video, we showed you how to divide your topic into facets, and how to develop a list of search terms for each facet. For the topic Native American Puberty Ceremonies we had these 3 facets, and these 3 lists of search terms. What you didn’t learn in that video was how to use those search terms in an actual search. These 3 lists of terms represented words that we believed might appear in articles on our topic, Native American Puberty Ceremonies. The words, however, could appear any number of combinations. For example,
Even a short list of search terms can generate an unwieldy number of combinations, in this case 45, and it would be prohibitively difficult to search them all separately2. With the third basic search technique, you will be able to combine all these terms into a single query, without having to run separate searches for every possible combination. This technique is called Boolean Searching.
Boolean Searching is the technique of using special connectors, or operators, to combine search terms in a logical order. The two most important Boolean Operators are OR, and AND. You will need to use both of these operators when searching library databases.
Let’s look first at the The OR Operator. The OR operator is used to combine search terms that represent the same facet. We can use this first facet as an example: This figure represents all documents containing the term Native Americans, and the next one represents all documents with the term Indians. Combining these terms with an OR operator tells the search engine I want documents that contain either the term Native Americans, or the term Indians. Using this technique, I will retrieve more documents than if I had searched with one term alone.
Remember that search terms can be either words or phrases, and that phrases should be enclosed in quotation marks. Remember also to truncate where appropriate. I will truncate "native americans" after the "n". I won't, however, truncate the word "indians" because I don’t want to retrieve articles on the state of Indiana. Instead, I'll just add "indian" as a separate search term. The OR operator tells the search engine to retrieve documents that have at least one of these search terms.
Let’s try this search in the database America: History and Life. As you can see, there are many records in this database that have one of these three terms. When searching in library databases, you will use the OR operator to search for multiple terms that represent the same facet of your topic.
Now let’s look at the AND Operator. The AND operator is used to combine terms that represent different facets. If I search for "indians" AND "puberty", I'm telling the search engine to retrieve only those documents that have both the term Indians and the term Puberty. To demonstrate this visually, this set contains all documents with the term Indians, and this set contains all documents with the term Puberty. The dark section in the middle represents the documents that contain both the term Indians AND the term Puberty. Using the AND operator narrows the scope of your search, and eliminates irrelevant results.
You will often use the OR operator and the AND operator together. Let's look at our list of search terms again, and this time let's remove the numbers. Using Boolean operators, I can tell the search engine that I want at least one term from list 1, and at least one term from list 2, and at least 1 term from list 3. In other words, retrieve documents that have at least one term from each of my 3 lists. Remember to use quotation marks around phrases, and truncate where appropriate.
If you look at a typical library database, like JSTOR, it should become clear how library databases are designed to accommodate Boolean searches. The AND operators are already in place. The search terms from my first facet, linked with OR operators, go in the first box; the search terms from my second facet go in the second box; and the search terms from my third facet go in the third box. If I had more than three facets, I would add another search box. This third search technique enables me to search every relevant combination of my search terms using a single query.
These are the three techniques you will need to search library databases. For more information, visit us in the History, Philosophy and Newspaper library.
1. During this search, we used search limits geography=North America, classification=photograhs, and time period=1900-1910.
2. The forty-five combinations of the search terms in the example shown in the video: