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Types & structures of information resources. What is out there for searching and what’s under the hood?. Definitions. resource – Encarta Dictionary “Source of help …somebody who or something that can be used as a source of help or information … adeptness at finding solutions to problems”

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types structures of information resources

Types & structures of information resources

What is out there for searching and what’s under the hood?

© Tefko Saracevic

definitions
Definitions
  • resource – Encarta Dictionary

“Source of help

…somebody who or something that can be used as a source of help or information

… adeptness at finding solutions to problems”

  • database – Webopedia.com

“A collection of information organized in such a way that a computer program can quickly select desired pieces of data. You can think of a database as an electronic filing system.”

© Tefko Saracevic

definitions cont
Definitions (cont.)
  • Information databases are organized by fields, records, and files. A field is a single piece of information; a record is one complete set of fields; and a file is a collection of records. For example, a telephone book is analogous to a file. It contains a list of records, each of which consists of three fields: name, address, and telephone number.

© Tefko Saracevic

relations
Relations
  • Terminology can be confusing & not consisted - so beware & do your own translation
    • Provider: aproducerofdatabases; there are great many providers covering many fields
      • e.g. Dept. of Education produces ERIC – abstracts & indexes educational materials (articles, reports)
    • Vendors or aggregators: organizations or companies that get databases from providers & organize them for searching; there are a number of vendors; some providers are their own vendors
      • e.g DIALOG gets over 400 databases from a variety of providers, (among them ERIC) & then organizes them for searching

© Tefko Saracevic

example of a vendor dialog
Example of a vendor: DIALOG
  • acquires databases, from information providers at a fee
  • organizes content according to given structures
  • describes the content
    • done in Bluesheets, a most important search tool for you
  • provides given searching capabilities
    • you have to master them for effective searching
  • creates some own files – e.g super indexes
  • provides you access at a fee
    • there is no such thing as free lunch

© Tefko Saracevic

btw why dialog
BTW – why DIALOG?
  • Why do we use DIALOG for so many exercises? Several reasons
    • oldest and largest surviving vendor
    • most comprehensive set of databases
    • has a well developed instructional program
    • but most importantly: serves as a good test bed to develop searching skills that are generalizable
    • what you will systematically learn from using DIALOG can be translated to all searching
      • & you get an insight into problems with searching

© Tefko Saracevic

other vendors aggregators
Good number of other vendors is around

the landscape is constantly changing

some available through RUL – examples (examine!)

LexisNexis

Factiva

ScienceDirect

EBSCOhost

Ingenta … and on

some incorporate databases from producers, others create own databases from myriad of sources

confusing?? wait, there is more…

Other vendors/aggregators

© Tefko Saracevic

types of information databases
Many types are available:

Bibliographic

Numeric

Full text

Directory

Image

Sound

Multimedia

Real time

Some that are in DIALOG are also available elsewhere or on their own

Some vendors have exclusive right to some databases

Many you find in RUL

Types of information databases

© Tefko Saracevic

examples of databases
Examples of databases
  • Over 200 available at RUL – examples that are relevant to library and information science
      • Library and Information Science Abstracts
      • Library Literature and Information Science
      • Information Science and Technology Abstracts
      • ERIC
      • IEEE Xplore
      • ACM Digital Library
      • but others also cover materials of interest e.g
        • Web of Science
        • INSPEC

© Tefko Saracevic

a big problem
a BIG problem
  • In DIALOG & some other vendors you can search a number of databases at the same time – so called federated searching
    • or in DIALOG search Dialindex – a meta index of databases
  • BUT in RUL & elsewhere there is no federated searching
    • you have to search each database separately
      • someday there will be federated searching, but at present do not hold your breath

© Tefko Saracevic

as would imagine
as would imagine …

© Tefko Saracevic

now unto structures getting under the hood
Now unto structures – getting under the hood
  • Each database type has its own structure
    • why? to describe various parts of content for computers to recognize
      • you can recognize that a section of a document is a title, but computer has to be told that a title is a title
      • so that it can (among others) search for terms in a title when you request so
  • Parts of documents (or objects in databases) are labeled as to as to content or function

© Tefko Saracevic

labeling schemes
Labeling schemes
  • Many structure schemes were developed that prescribed what to label & what to call the label – meta languages
    • by providers, vendors, organizations, authorities
    • in different subjects, domains
    • for different types of objects
  • Meta tags are used on the web – to describe & index
    • semantic web is in development, to further enable description of and searching for meaning
  • MARC is a form of meta language
  • To use these schemes for effective searching you have no choice but to get familiar

© Tefko Saracevic

transparency of structures
Transparency of structures
  • In some databases description of structure is readily available
    • even though it may look forbidding, complicated
      • good example: Bluesheets in DIALOG
  • In others, structure is there but has to be discovered by surmising
    • even in
  • But clever, appropriate use of structure in searching is key to effective searching

© Tefko Saracevic

example file 438 bluesheet library literature and information science
Example: file 438 BluesheetLibrary Literature and Information Science

Describes the content of the file

© Tefko Saracevic

file 438 fields each is searchable

SAMPLE RECORD [top]

Sample record:

indicates structure

file 438 fields- each is searchable

© Tefko Saracevic

file 438 fields in basic index
file 438: fields in Basic Index

Basic index is searched by default – examples how to search fields in basic index

© Tefko Saracevic

file 438 fields in additional indexes

Additional index is searched by indicating the field to be searched – examples how to search them

file 438: fields in Additional Indexes

Neat trick:

If you want to search the latest update only, add to search UD=9999

© Tefko Saracevic

file 438 fields in limit
file 438: fields inLimit

Searches can be limited to cover documents with given attributes – examples how to limit searches

© Tefko Saracevic

file 438 additional uses of structure
file 438: additionaluses of structure

Results can be sorted or ranked by given fields – examples how to sort or rank results

© Tefko Saracevic

file 438 options in displaying of results
file 438: options in displaying of results

Results can be displayed in a number of ways – examples of available formats

But watch out! In real life some formats are free other cost $$$$!

© Tefko Saracevic

economics tail that wags the whole dog
Economics – tail that wags the whole dog
  • In class DIALOG searching is free
    • & you can use it for class exercises, nothing else
  • In real life DIALOG(as every other vendor)has an elaborate economic structure
    • different files have different price tags for use
    • time of use is calculated in DialUnits
      • a Byzantine structure of charges beyond understanding
    • in different files different formats have different price attached
      • some are rely hefty!

© Tefko Saracevic

where to find all about structure
Where to find all about structure?
  • In DIALOG in BlueSheets
    • consult often! and again! and again! and again!
    • files have similarities and differences in structure – BlueSheets show that
  • For other vendors:
    • some have similar description as BlueSheets
    • some have to be dug up & surmised
    • in some revelation comes from checking what is available in advanced searching or in tips for searching

© Tefko Saracevic

structure in search engines
Structure in search engines
  • Mostly not readily apparent
    • but all have capabilities to be used in searching
  • Again: revelation comes from checking what is available in Advanced Search, Search Features, Search Tips, Help, & the like
  • Most users do NOT take advantage of using available structures in searching
    • professional searchers do
      • part of their tool kit & competencies

© Tefko Saracevic

example structure from advanced search
Example: structure from Advanced Search

Records are structured at minimum by these fields

© Tefko Saracevic

another example structure from advanced search
Another example: structure from Advanced Search

Records are also structured at minimum by these fields

© Tefko Saracevic

similarities differences
All vendors & search engines have a basic search by default & an advanced search

but defaults & advanced capabilities differ & have to be confirmed for each

once you learn, you will apply variations on the theme

Similarities & differences

© Tefko Saracevic

similarities differences28
All vendors & search engines have basic & advanced Boolean-type search capabilities

but how it is done & bells and whistles differ

once you master concepts you can then do an AHA! when you encounter a variation & then translate

Similarities & differences …

© Tefko Saracevic

similarities differences29
All vendors & search engines rank output results

but how it is done differs

DIALOG uses LIFO – Last in First Out as default, but also allows for other ways

search engines use ranking by relevance, clustering, PageRank … criteria

not easy to discern

Similarities & differences …

© Tefko Saracevic

similarities differences30
Most users

do not know or care about structure

do not search beyond default capabilities

do not look beyond one or two pages of results

miss many potentially relevant results

do not know what is under the hood

Professional searchers

know that structure is very much connected to searching

learn about & use available structures

understand defaults & use advanced capabilities as necessary

know “tricks” for not missing stuff or not getting to much or to much junk

explore in order to learn what is under the hood

Similarities & differences …

© Tefko Saracevic

in conclusion
In conclusion!

Searching is more art than science, but an art that needs a lot of knowledge what is behind it

© Tefko Saracevic

slide32

Thanks!

© Tefko Saracevic