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LIS618 lecture 1

LIS618 lecture 1. Thomas Krichel 2003-09-20. Structure of talk. Recap on Boolean Before online searching Working with DIALOG Overview Search command Bluesheets Basic and additional index. before a search I. what is purpose brief overview comprehensive search

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LIS618 lecture 1

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  1. LIS618 lecture 1 Thomas Krichel 2003-09-20

  2. Structure of talk • Recap on Boolean • Before online searching • Working with DIALOG • Overview • Search command • Bluesheets • Basic and additional index

  3. before a search I • what is purpose • brief overview • comprehensive search • What perspective on the topic • scholarly • technical • business • popular

  4. before search II • What type of information • Fulltext • Bibliographic • Directory • Numeric • Are there any known sources? • Authors • Journals • Papers • Conferences

  5. before search III • What are the language restrictions? • What, if any, are the cost restrictions? • How current need the data to be? • How much of each record is required?

  6. two steps in DIALOG • step one: select databases (aka files) to look at • step two: perform searches on the selected databases • You may wonder why one does not have one single step like in a search engine. Discuss. • today we concentrate on the second step

  7. working on selected files • We assume that we have selected database that we know and we look at the search interface on the selected database. • The database selection process is a bit more complicated, covered next week. • First, let us login and look at the command prompt. • Then we select the first database (file) with the begin command

  8. The begin command • As its name suggests, usually the first command. • begin number, number,… • selects files with numbers number • Once they are selected they can be searched. • Now select the ERIC "begin 1" • "Begin 1" can be abbreviated as "b 1"

  9. Substeps in the second step • Identify search terms • Use Dialog basic commands to conduct a search • View records online or print the results

  10. the 's' (select) command • Once issued the "begin" command to select a database, we issue the "s" command on the database. • "s query_terms" where query_terms are the query terms • This will search the index of selected database in full-text view for the query issued • It will not find any of the following: "an and by for from of the to with". They are stop words.

  11. connectors • If you want to use several keywords there are three ways • you can truncate search terms • you can build an expression by putting several keywords together. This is achieved by DIALOG's connectors. • you can combine several expressions with the use of Boolean operators • we will cover this is in turn now

  12. truncation of terms • Open Truncation • "select path?" retrieves all words that begin with path: paths, pathos, pathway, pathology • Controlled-Length Truncation • "select path??" retrieves the root and up to two additional characters: paths, pathos

  13. truncation of terms II • Embedded Character truncation can be used for variant spellings: • "select organi?ation" -> organization organisation  • "select fib??board" -> fiberboard fibreboard  • This truncation feature is also useful for searching for unusual plural forms: • "select wom?n" -> woman women • You can also do prefixes by putting the ? in the beginning. • "?mobile" -> automobile metamobile

  14. Use of connectors • Connectors are used to put several words together. • One instance where this is useful is when you have words that on their own mean different things. • For example "mate" is a herbal beverage consumed in South America. Looking for mate on the Internet retrieves a lot of singles' pages.

  15. example: terms related to "mate" What other terms to be used? • matear (drink mate) • matero (mate drinker) • cebar (prepare mate) • cebador (mate preparer) • yerba (mate herb) • bombilla (mate straw)

  16. connectors I • '(W)' requires terms to appear one after the other next to each other e.g. 'yerba(W)mate?' matches "yerba mate". • '(i W)' where i is an integer, means followed by at most i words, e.g. 'ceba?(3W)mate?' matches "cebar un maravilloso mate" but not "cebador guapo mirando un buen mate"

  17. connectors II • '(N)' requires terms to be next to each other e.g. 'yerba(N)mate?' matches "yerba mate" or "mate yerba". • '(i N)' where i is an integer, means proximity by at most i words, e.g. 'ceba?(3N)mate?' matches "cebar mate" or "matear con la cebadora". • '(S)' searches for the occurrence of connected terms in the same paragraph.

  18. using Boolean operators • In your query, you can combine several expressions with Boolean operators • Example: "S LIBRARY(W)SCHOOL? AND DISTANCE(W)EDUCATION" • But I usually do not issue such fancy queries.

  19. executing several searches • there can be several searches done sequentially, and the results sets are saved by the system. • Each time the system assigns a set number, Si, • These can be combined in Boolean expressions, e.g. 's S1 or S2 and S3' • Remember that Boolean operations are set-theoretic!

  20. Boolean operators on sets • when using Booleans, be aware that "and" has higher precedence than "or". • Thus: a or b and c is not the same as (a or b) and c but it is a or (b and c) • use parenthesis when in doubt

  21. DS (display sets) • This command can be executed any time to review the sets that have been formed since the last B (begin) command. • This can be useful to review your search history.

  22. the target command • "target set" where set is a search result set creates a subset of the "statistically most relevant results" in the original set. • I have not seen details about how this subset is computed. • new result set is being formed.

  23. display: the type command type set/format/range • set is a result set • format is a format • range can be • start – end • start is a record number to start • end is a record number to end • all

  24. standard delivery formats • 2 -- full record except abstract • 3 or medium – citation • 5 or long – full except full text • 6 or free – title and dialog number • 8 or short – title plus indexing terms • useful to find other indexing terms • 9 or full – everything • KWIC or K – keywords in context

  25. options for delivery • I once tried to email results to me, to no avail • You can save the html of the search results in the browser. • You can print the results within the browser.

  26. http://openlib.org/home/krichel Thank you for your attention!

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