LIS618 lecture 4before searching +

introduction to dialog

Thomas Krichel2011-11-01

logon and off

• When you are logged out, by timeout usually you can use the “logon” command to come back.

• “logoff” can be used to log off. • “logoff” will be run by the system after 10

minutes.

bluesheet

• Each database name is linked to a blueish pop-up window called the blue sheet for the database.

• This is called the bluesheet. • It contains the details of the database.• File 415 has the bluesheets. But they are also

on the web.

database lists

• Sometimes, you want to find out if a certain publication, say, a serial, is available on Dialog

• http://library.dialog.com/bluesheets/ has a search box specifically for journal data.• http://library.dialog.com/bluesheets/html has

a nice old-fashioned interface.

Looking at database structure

• Up until now, we have looked at commands that take a full-text view of the database.

• Such commands can be executed for every database.

• If we want to make more precise queries, we have to take account of database structure.

closer look at the bluesheet

• File description• Subject coverage (free vocabulary)• Format options, lists all formats – by number (internal)– by dialog web format (external, i.e. cross-

database)• Search options– basic index, i.e. subject contents– additional index, i.e. non-subject

basic vs additional index

• The basic index – has information that is relevant to the substantive

contents of the data– usually is indexed by word, i.e. connectors are

required• The additional index– has data that is not relevant to the substantive

matter– usually indexed by phrase, i.e. connectors are not

required

search options: basic index

• SELECT without qualifiers searches in all fields in the basic index

• The bluesheet lists field indicators available for a database.

• Also note if field is indexed by word or phrase. proximity searching only works with word indices. When phrases are indexed you don't need proximity indicators

search in basic index

• A field in the basic index is queried through term/IN, where term is a search term and IN is a field indicator

• Thomas calls this a appending indicator• Several field indicators can be ORed by giving

a comma separated list• For example mate/ti,de searches for mate in

the title or descriptor fields

limiters and sorting

• Some databases allow to restrict the search using limiters. For example– /ABS require abstract present– /ENG English language publication

• Some fields are sortable with the sort command, i.e. records can be sorted by the values in the fields. Example: sort s1/all/ti.

• Such features are database specific.

additional indices

• Additional indices lists those terms that can lead a query. Often, these are phrase indexed.

• Such fields a queried by prefix IN=term where IN is the field abbreviator and term is the search term

• Thomas calls this a pre-pending indicator

expanding queries

• Names have to be entered as they appear in the database.

• The "expand" command can be used to see varieties of spelling of a value

• It has to be used in conjunction with a field identifier, example– expand au=cruz, b?– expand au=barrueco?

to search for misspellings of José Manuel Barrueco Cruz

expanding queries II

• search produces results of the form Ref Items Index-term– Ref is a reference number– Items is the number of items where the index

term appears– Index-term is the index term

• "s Ref" searches for the reference term.

expand topics

• You can also expand a topic in a database to see what index terms are available that start with the term. Example “b 155 ; e cold”

• If you expand an entry in the expansion list again, you can see a list of related terms to the term, if such a list is available.

Example

• How many domain names are currently registered in Novosibirsk, Russia?

• Hint: use domain name database file 225.• Note that this database also covers non-

current domains.

ranking

• The rank command can be use to show the most frequent values of a phrase indexed field in a search set.

• Example– rank au s1 shows the most frequent authors– rank de s1 shows most frequent descriptors

• read the screens following rank command for instructions.

example

• Who wrote on interest rates and growth rates. Use EconLit “b 139”

• “s interest(n)rate? and growth(n)rate?”• “rank au s1”• You can then set some authors you are

interested in, “1-5” for example• “exit” to leave rank, confirm with “yes”.• “exs” to search for those authors.

topic searches

• Often we want to know what literature is available on a certain topic.

• Many times authors do not use obvious words that occur to the searcher.

• Using descriptors can be very helpful.– Conduct a search– Look for descriptors– Use those in other searches

Initial file selection

• On the main menu, go to the database menu.• After the principle menu, you get a search box• There you can enter full-text queries for all the

databases• You can then select the database you want• And get to the begin databases stage.

database categories

• In order to help people to find databases (files), DIALOG have grouped databases by categories.

• categories are listed at http://library.dialog.com/bluesheets/html/

• 'b category' will select databases from the category category at the start.

• 'sf category' selects files belonging to a category category at other times.

add/repeat

• add number, number adds databases by files to the last query• example "add 297" to see what the bible says

about it• repeat repeats previous query with database added

to find publications

• Sometimes, you want to find out if a certain publication, say, a serial, is available on Dialog

• http://library.dialog.com/bluesheets/ has a search box specifically for journal data.

example

• what is written about the role of libraries in distance education?

• b 1,438• ? s librar? and distance(N)education– 250570 LIBRAR?– 15233 DISTANCE(N)EDUCATION– S1 2053 LIBRAR? AND DISTANCE(N)EDUCATION

http://openlib.org/home/krichel

Thank you for your attention!