Ranked Keyword: Help 

A Ranked Keyword search looks for words and phases located anywhere in a catalog record. A Ranked Keyword search may be useful when other search methods have not retrieved as much material as desired. This search is designed to retrieve the largest number of records possible, displaying them according to the system's evaluation of their relevance. Search limits are available.

About Relevancy Ranking:

Ranked Keyword search results are displayed as a Ranked Keyword Title List in an order determined by a relevancy algorithm. Although relatively new to library online catalogs, relevancy ranking is used by many Web search engines (e.g., AltaVista, Lycos, etc.) However, each system’s formula for determining relevance is a little different. Here is some information on the ranking factors used in Orbis:

• Uniqueness of search terms within the database
• Proximity of search terms to each other within the catalog record 
• Number of different search terms present in a catalog record
• Number of times a search term occurs in the catalog record fields (e.g., subject heading field, author field, title field).

Search Strategies:

Because the Ranked Keyword search is set up to look for any of the words entered and because of the very large size of the Yale University online catalog, Ranked Keyword search results can be very imprecise. It is strongly recommended that special punctuation symbols be used to ensure more precise searching.  To perform a Ranked Keyword search, enter the search words or phrases including the following punctuation:

quotation marks  ( " ) surround exact phrases: "richard the lionheart"

+ indicates words that must appear: +medicine +alternative

* indicates important words: *renaissance

! indicates words that must not appear: buddhism !zen

? indicates word truncation: byzant? (searches for Byzantium, byzantine, etc.)

• Enter words or phrases in any order.
• All words will be searched including "and", "or", "not", "the", "a", "la", "das", etc. Boolean operators do not work in Ranked Keyword searches.
• Omit intervening commas, periods, apostrophes and most other punctuation. Retain hyphens and internal commas or periods (commas or periods within numbers), but those terms must be bounded by quotation marks.

  "1,001 broadways" or "1.001 poemas"
  "al-jazeera"

• To improve the relevance of the results it is usually better to use more words or phrases in the search strategy, as well as using the suggested punctuation tools.

Ranked Keyword Examples:

Ranked Keyword searching should be used with caution for these reasons: 

• The Orbis catalog is very large (several million records).
• It is very important to use punctuation, particularly the plus (+) to indicate that a word or phrase must appear in every record retrieved, to limit the size of the retrieval.
• Every additional word included in the search serves to expand the results (that is, an implied Boolean "or" is in effect). This can result in a huge result set that may slow response time and be difficult to navigate.
• Words entered without quotation marks (") are searched as an "or" search.
• The total number of retrievable catalog records is limited to 10,000. 
• The method the system uses to rank the relevance of materials is complex and may not always accord with the searcher's estimation of relevance.