Narrowing the Search

Tom Kelliher, CS 102

Feb. 2, 1998

Announcements:

From last time:

1. Quiz.

Outline:

1. Return quiz. Discuss.

2. Search engine operators.

3. Search engine exercise (will probably carry over).

Assignment:

Quiz: Return and Discussion

Search Engine Operators

Why would I want to use this?

Note:

1. Not all engines support all operators.

2. Most engines have Simple and Advanced searches.

3. Look for help pages.

Basic ideas:

1. Character case is ignored if keywords are all lowercase.

2. A single keyword: birdwatching.

3. Two keywords: bird watching.

4. Multiple keywords.

5. a compound single keyword: "bird watching". ``Exact phrase.''

6. Example: AltaVista.

7. Natural language queries: type a question in ``ordinary'' English. What is the weather in Pittsburgh? weather Pittsburgh? Maybe it'll work.

Operators:

1. +: Use as a prefix to a keyword. Document must contain the keyword.

   What's the difference between

   1. bird watching

   2. +bird watching

   3. +bird +watching?

2. -: Another keyword prefix. Document must not contain the keyword.

3. *: A keyword suffix. Wildcard which expands the search.

   Example: gold* matches: gold, golden, goldfinch, etc.

4. AltaVista predicates: keyword modifiers. Examples:
   1. title: --- the keyword must be in the document title. Example:

      title:"bird watching"
      

   2. text: --- the keyword must be in the document text.

   3. domain: --- the document must be on a computer in the specified domain. Example: domain:gov .

   4. host: --- the document must be on the specified computer. Example:
      host:www.goucher.edu .

5. Excite's ``More like this,'' once you've gotten some results back.

Boolean operators (sometimes an advanced search feature):

1. AND --- keywords connected by this must all appear in the document.

2. OR --- one or more keywords connected by this must appear in the document.

3. AND NOT --- the following keyword must not appear in the document.

4. NEAR --- keywords connected by this must appear in close proximity within the document.

5. Parentheses may be used to organize groups of keywords connected by Boolean operators.

Search Exercise

Working in groups of three, research the topic Personal privacy in the electronic age. Use at least three search engines. A different person should take the lead in conducting the search at each search engine site. The two remaining team members should assist. Use the search operators available at each engine to narrow your search so that fewer than 100 documents are returned. Post a summary of the results of your search to the class bulletin board. In your posting, discuss the following:

1. How you converted the topic statement to a keyword or keywords.

2. Which search engines you used.

3. Your initial and final search queries and the counts of how many documents were returned for each query.

4. A quick assessment of the relevance of the first three documents returned by each of your three final search queries.