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Learn about Bluesheets, database lists, and search options for precise queries in Dialog databases. Understand field indicators, proximity searching, limiters, and expanding queries for effective information retrieval.
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LIS618 lecture 4 before searching + introduction to dialog Thomas Krichel 2011-11-01
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 bluesheetlists 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 categoryat the start. • 'sfcategory' selects files belonging to a category categoryat 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!