Sunday, December 14, 2014

Dialog lecture

Basic search example
B to begin
# for database (separate multiple by commas; shorten to abbreviations if searching similar databases)
n for database file number
? searches [search terms]
brackets indicate subject headings
Dialog tells you how many records are available
?T for type view results
s1 = set 1 records
s = view titles and descriptors (free format, browse)
1 = print
SELECT

Set Items Description
Set number  Number of records containing hits Term(s) as entered in the SELECT COMMAND

Always enter a space after command. Any word/term except stop words can be selected. Phrases must be selected using the (w) command unless the term is a descriptor or identifier.

Multiple terms can be selected when using logical commands. To create a set for each term in the command, use SELECT STEPS (change, recombine terms e.g. bilingualism in Canada, then bilingualism in Belgium).

Open truncation ? retrieves all words beginning with, e.g. with comput? (computers, computer, etc.);
symbolises unlimited length with no intervening
Controlled-length truncation Retrieves all words beginning with a maximum number of letters following word stem
? [space] ? retrieves all words beginning with ? with maximum of one character following word stem
Imbedded character ? for character replacement letter for letter to retrieve either spelling e.g. organisation, organization
If more than one letter, use OR e.g., favor OR favour

Viewing records: TYPE command
Command format
?type s5/2/1-4

s5 /  2 /  1-4
Set number Format Items inclusively; item numbers can be a single record, a range (e.g., 1-4, 6, 9 or ALL/all)

If omitted, default becomes
Item Next record display
Format Format set typed
Set Last set created

LOGOFF log off system
Enter one select command for each concept, combining synonyms and alternative terms with OR logic.
Select the set numbers representing different concepts, combining them with AND logic.

Searching styles
Concept blocks  Break down logically with Boolean searching
Pearl growing "Gem" search for perfect record meeting search criteria
Successive fractions Extremely broad search - breakdown into finer divisions with more limits
Known item matching Situation known item, looking for specific item to verify existence

Stacking Enter several commands in a single line of typing separated by semicolons. A line can contain up to 240 characters.

Narrow search  Broaden
AND concept No concepts; limit
Use fewer terms Use more terms or subject headings
Use proximity operators Truncate left
Truncate right Use broader terms
Qualify/limit Remove qualifiers, limitations

Search the basic index/suffice fields
Select commands searches the entire Basic Index unless the term is qualified by a suffix. Using a suffix is an option when searching the Basic Index. To qualify a term to a given field, enter a slash (/) followed by two letter field suffix. Use a comma to specify either field.

Selecting descriptor terms
Include spaces and punctuation if exact descriptor single word restricted with descriptor, retrieves word anywhere in descriptor term, use DE

Retrieve single word using DF / IF

Searching numeric indexes
: Low/high ends range, e.g. 1986:1991
> Greater than
< Less than
>= Equal to/greater than
<= Equal to/less than

Proximity
Exact phrases anywhere,
Adjacent/hear other words,
(sub)heading descriptors

Use for-:
Exact phrases anywhere,
Files not employing controlled vocabulary,
Phrases containing stop words, punctuation, hyphens and special characters
Phrases not in thesauri
Particularly new terms
Unusual expressions
Subjects marginally covered

Searching full-text files when using logical operators may be dangerously broad

Narrowing a search to decrease recall and increase proximity precision

Repeat proximity to connect series

Use parentheses

Correct order
– W, N, L, S, F

Use parentheses around connected terms to be processed first

Replace punctuation marks with a (W) operator.

To select from a phrase-indexed field, enter the exact bound phrase with all punctuation intact, if containing slash, apostrophe, or logical operator, enclose the phrase in quotation marks.

Precision versus Recall Search examples
Select command(s) Records Explanation
east and germany 3691 Two words appear in the same record
east(f)germany 3364 Two words appear in same Basic Index Field
east(w)germany 1852 Phrase appears in Basic Index
east(w)germany/ti 559 Phrase appears in title field
s east germany 2 Phrase appears as a Descriptor or Identifier

Searching on terms containing punctuation

To select from a word-indexed field, replace each punctuation mark with a (w) operator.

To select from a phrase-indexed field, enter the exact bound phrase with all punctuation intact. If the phrase contains a slash, apostrophe, or logical operator, enclose the full phrase in quotation marks.

Expand command

Expanding in the Basic Index: ?expand microcomputer

The EXPAND display pauses after every 12 lines. Use PAGE (or P) to see the next 12 lines. Up to 50 lines can be displayed.

Expanding to view the Online Thesaurus

To view the related terms, EXPAND the E number. Each related term is assigned a R reference number. An R-numbered list includes a code describing the relationship.

Expanding on terms containing punctuation

Do not use proximity operators or truncation.

The strings of characters entered after EXPAND is interpreted literally and simply inserted into the index where it fits alphabetically.

Selecting terms after expanding

To retrieve a single entry from an expand list, Select its E/R number. Be sure to SELECT before entering EXPAND. Each EXPAND command creates a new list and erases the previous one.

Selecting multiple terms

Retrieve multiple entries from same EXPAND list synonymously related, use OR logic. Retrieve sequential entries, use colons.

Expanding in additional indexes

Use EXPAND to check entry form for fields containing names.

For author’s name, enter surname and first initial.

For company’s name, enter first part then try variation with abbreviations, punctuation.
For journal name, start by EXPANDING on first word. Notice if database uses abbreviations. If needed, enter a different EXPAND.

Limits

Available to facilitate broad restrictions to retrieval. Entered as suffixes in a SELECT command. Limits are highly database specific.

Determine what limits are available – read Bluesheets, enter command HELP LIMIT n (with n being file number)

Enter suffixes in SELECT commands after /

Use /ENG more than LA=English. Use LA= field for other languages. EXPAND to verify entry form.

Current= current year plus the previous year

Expand fields if you’re not sure what a field has available.

Restrict publication date, SELECT from appropriate Additional Index. In databases with PY= field, enter years without prefix as a LIMIT suffix.



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