Technology Tips

Dan Comden, adaptive technology specialist, UW

Scholar Question:
I'm doing a report and a speech. I want to find certain information on a certain topic. I use WebCrawler all the time. But when I use WebCrawler, I get all this other stuff not even close to what I wanted. Suggestions?

To do topic-specific hunting you need a relevant search engine. Search engines are offered at various Web sites. The two I use most often are MetaCrawler and Alta Vista. But no matter which engine you use, the trick to doing searches is learning how to phrase your search terms so that you get items you want and minimize the amount of "noise" or unwanted material.

Example: Using quote marks
Here's something you could try yourself at the Yahoo search site at
Suppose you want to find out more about geology. If you just search on the term [geology], it's possible to get more than 100 K (that's 100,000) instances of the word "geology" with potentially relevant information. But who has time to go through all that? If you're really interested in the formation of horst and graben terrain, you could enter the phrase ["horst and graben"] (leaving the quotation marks in) and get fewer references ("hits").

Using quotation marks to delineate search terms will narrow your search results tremendously--down to 20 hits of your search term. It may also be helpful to have a dictionary or thesaurus on hand to come up with alternate terms to use for your search.

Advanced Queries
The Advanced Query feature on Alta Vista allows more elegant searching. You can use keywords like AND, NOT, and OR to restrict or expand your search criteria. Here's an example which demonstrates the difference between AND, NOT, and OR.

If you want to find articles or pages that have information about planetary geology and volcanism, your search might look a little more complicated: ["planetary geology" volcano] (make sure you use quote marks to indicate text you want to stay together).

This first search without any Boolean operators (that's what AND, NOT, and OR are really called) will yield about 76,000 hits where the phrase "planetary geology" and/or the word volcano appear in a document. Now let's try the Advanced Search. You can select it from the top of the Alta Vista page.

Use of AND operator
If you want to search for documents where the phrase "planetary geology" and the word volcano BOTH appear, it's a simple process. AND is a restrictive operator, in that in order for a location to be a hit, it must satisfy both sides of whatever is around the AND statement. For our example, in the advanced search box, if you enter ["planetary geology" and volcano] (leave out the brackets but put in the quotation marks), your search has been narrowed down to 85 or so hits or results". This makes things quite a bit easier.

Use of OR operator
OR is an inclusive operator and will help you collect more information. If you want to expand your search you could use "OR", but you would get *MANY* hits. In the example above, the advanced query ["planetary geology" OR volcano] yields about 30,000 hits matching the query terms. Quite a difference between using AND and OR, eh?

Use of NOT
This Boolean operator started out as a trendy phrase on Saturday Night Live NOT! Actually, it's been around quite a bit longer than that. The NOT operator allows you to completely restrict terms from your search and is often useful when combined with other operators. For our example, if you wanted information on planetary geology and volcanoes but wanted to ignore anything to do with the moon, you could construct a search with the terms: ["planetary geology" AND volcano AND NOT lunar]. Now you're down to about 56 hits.

As you can see, searching the Web can take a little practice, but once you get familiar with AND, NOT, and OR and use some creative search terms, you will find Web surfing quite a bit more enjoyable.