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LIS618 lecture 4
Thomas Krichel
Structure of talk
• Before online searching
• Introduction to online searching
• Introduction to DIALOG
– Overview
– bluesheets
before a search
• what is purpose
– brief overview
– comprehensive search
• What perspective on the topic
– scholarly
– technical
– business
– popular
before search
• What type of information
• Are there any known sources?
before search
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?
Dialog is a databank
• over 500 databases
• these are also known as files and cover
– references and abstracts for published
– business information and financial data;
– complete text of articles and news stories;
– statistical tables
– Directories
• DIALOG uses the Boolean model
DIALOG interface
• is still rooted in "traditional" database
• dismissed as "dial-a-dog"
• is uses a command-driven interface
• it is very complicated to learn fully
• it is not suitable for the end-user
• it therefore offers a valuable skill to the
information professional
• it is a challenge for a professor to teach
Accessing DIALOG
• On the web, go to
• Enter username and password, then click
on logon
• When it is all done, click logoff in the top
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.
• today we concentrate on the second step
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
• Then we select the first database (file) with
the begin command
The begin command
• As its name suggests, usually the first
• begin number, number,…
• selects files with numbers number
• Once they are selected they can be
• Now select the ERIC "begin 1"
• "Begin 1" can be abbreviated as "b 1"
Substeps in the second step
• Identify search terms
• Use Dialog basic commands to conduct a
• View records online or print the results
the 's' (select) command
• Once issued the "begin" command to select a
database, we issue the "s" command on the
• "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.
• 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
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
one additional character: paths
– "select path??"
retrieves the root and up to
two additional characters: paths, pathos
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
– "?mobile"
automobile metamobile
Use of connectors
• Connectors are used to put several words
• 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.
terms connected to mate
• What other terms to be used?
– matear
– matero
– cebar
– cebador
– yerba
– bombilla
(suck mate)
(mate sucker)
(prepare mate)
(mate preparer)
(mate herb)
(mate straw)
• '(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"
• '(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.
using Boolean operators
• In your query, you can combine several
expressions with Boolean operators
• Example: "?SELECT
• But I usually do not issue such fancy
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
• These can be combined in Boolean
expressions, e.g. 's S1 or S2 and S3'
• Remember that Boolean operations are
Boolean operators
• 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)
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
formats are defined
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
Thank you for your attention!