lis618p03s 08

LIS618 lecture 8: 

LIS618 lecture 8 Thomas Krichel 2003-04-02

Lexis/Nexis: 

Lexis/Nexis Lexis is a specialized legal research service Nexis is primarily a news services adds an important temporal component to all its contents restricts contents as compared to Dialog potentially bad competition from Google

compilation of Nexis: 

compilation of Nexis Uses a number of news sources such as newspapers. Uses company reports databases Uses web sites, the URLs of which are found in the news sources. Some of the material there can be of low value (remember the comments in the first lecture)

SmartIndexing: 

SmartIndexing There is a controlled vocabulary of indexing terms A document is indexed In full text view (except web sites) With automatic addition of index terms that correspond to the document. Index terms are added Weight of index terms is calculated http://www.lexis-nexis.com/infopro/products/index/ has more on it.

Six interfaces to Nexis: 

Six interfaces to Nexis Quick search Subject directory Power search Personal news Search forms Real time news In the remainder of the lecture I will go through these interfaces…

Quick search: 

Quick search Implicit OR between terms Use quotes to require adjacency of terms You can select from a drop-down box of sources You can set the date range. It seems to OR a plural to your search term. Sometimes returns documents with none of the search terms. “she is the one”

Quick search: 

Quick search It is not clear what parts of documents are being searched It does seem to search the full text. But it seems to prioritize TERM, i.e. smart keywords extracted, HLEAD for news TITLE for legal documents WEB-SEARCH-TEXT for web pages

relevance ranking concerns: 

relevance ranking concerns where terms appear within the document how many occurrences of the terms appear in the document how often those search terms appear throughout the document apparently not how much they occur, example search for "the" seems that they guard algorithm a secret

Subject directory: 

Subject directory you can follow the subject tree but there seems to be only a tiny amount of documents categories are not particularly deep or developed there is a "more like this" feature of limited use, Thomas finds

Power search: 

Power search You can first create a customized set of sources to search Do this at the start, you browse a menu, then click “done, search now” This is a lot more efficient than trying to build a search strategy on a large set.

Power search connectors: 

Power search connectors OR AND AND NOT PRE/n, n is a number, ordered proximity W/n, n is a number, unordered proximity W/S words in same sentence W/P words is the some paragraph Use parentheses! There is no implicit or as in the simple search, so forget about the double quotes.

Power search expressions: 

Power search expressions Parentheses group terms together * for one or no letter ! for any number of letters ATLEAST n, where n is a minimum number of occurrences PLURAL (term) only the plural of term SINGULAR (term) only the singular of term ALLCAPS (term) only capitals of term NOCAPS (term) no capitals of term CAPS (term) capitalized term only

power search for news: 

power search for news uses power search expressions, plus hlead (expression) ? headline (expression) company (expression) for a company byline (expression) for the author show (expression) for a television show transcript expression is a Boolean expression or simple keyword.

power search for legal data: 

power search for legal data uses power search expressions, plus name (expression) for the name of a party cite (expression) for a citation expression for case law title (expression) for the title of a law article expression is a Boolean expression or simple keyword

Search forms: 

Search forms There are special forms for News Company reports Market indicators Portfolio News and quotes about companies

Personal news alert: 

Personal news alert do a search then click on “track in personal news” to get to a screen where you can enter periodicity what documents to be sent subject

Real time news: 

Real time news This uses a different query language terms are implicitly ANDed explicit AND and OR allowed phrases have to be put in quotes * starts for any number of characters, not just one as in power search parenthesis can be used I have poor experience with this.

Summary: 

Summary It has access to sources that are not freely available but The search interface is poor when compared to what is offered by Google. So you spend a lot of time working with it to get what you want.