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Use the EXPLODE Command to Retrieve Comprehensive Results?
TOPIC: A technique that can help you narrow your results is the EXPLODE feature. This feature is designed to take advantage of the hierarchical organization of online thesauri. It speeds retrieval by automatically selecting a term plus narrower related terms. Results vary depending on the type of thesaurus in the database. To EXPLODE a term, SELECT the term with an ending exclamation point (e.g., fuel!).
Dialog thesauri are constructed in two forms. In one form, using the EXPLODE feature will retrieve all of the narrower terms for all hierarchies (e.g., GeoRef (File 89)). In the other form, EXPLODE retrieves only the narrower terms immediately below the descriptor. It works this way because the thesaurus does not group all hierarchies under one descriptor, but rather retains levels of hierarchies, all of which may have narrower terms (e.g., Inspec® (File 2)). The EXPLODE feature works equally well with both types of thesauri, but you need to be aware of which thesaurus type you are exploding from, and then review your results accordingly.
In this example we'll be looking for narrower terms for "semiconductors" in Inspec.
COMMAND SUMMARY
BEGIN 2
EXPAND (SEMICONDUCTORS)
SELECT (R1, R3:R12)/DF
SELECT SEMICONDUCTORS!
HOW TO...
1. BEGIN File 2, which has a thesaurus that retrieves narrower terms immediately below the descriptor.
2. EXPAND on a term within parentheses to directly access the Related Terms display (rather than expanding twice). R1 includes all occurrences of the term in the Basic Index. |
?b 2
File 2:INSPEC 1898-2008/Apr W4
(c) 2008 Institution of Electrical Engineers
Set Items Description
--- ----- -----------
?e (semiconductors)
Ref Items Type RT Index-term
R1 534671 22 *SEMICONDUCTORS (January 1969)
R2 222 F 2 SEMICONDUCTOR ALLOYS
R3 31418 N 15 AMORPHOUS SEMICONDUCTORS (January 1973)
R4 983 N 8 DEGENERATE SEMICONDUCTORS (January 1977)
R5 4167 N 9 HEAVILY DOPED SEMICONDUCTORS (January 1977)
R6 5100 N 16 MAGNETIC SEMICONDUCTORS (January 1977)
R7 1092 N 8 MANY-VALLEY SEMICONDUCTORS (January 1977)
R8 3751 N 9 NARROW BAND GAP SEMICONDUCTORS (January 1977)
R9 991 N 8 POLAR SEMICONDUCTORS (January 1977)
R10 3912 N 13 POROUS SEMICONDUCTORS (January 1999)
R11 19836 N 23 SEMICONDUCTOR QUANTUM DOTS (January 1991)
R12 42919 N 8 WIDE BAND GAP SEMICONDUCTORS (January 1995)
R13 3450 R 17 ACOUSTOELECTRIC EFFECTS (January 1969)
R14 5182 R 20 CONDUCTORS (ELECTRIC) (January 1969)
R15 32817 R 14 PHOTOCONDUCTIVITY (January 1969)
R16 6032 R 11 PHOTOVOLTAIC EFFECTS (January 1969)
R17 14028 R 44 SEMICONDUCTOR DEVICES (January 1969)
R18 48267 R 45 SEMICONDUCTOR MATERIALS (January 1969)
R19 1324 R 5 SEMICONDUCTOR PLASMA (January 1995)
R20 1728 R 8 SEMIMETALS (January 1969)
R21 63144 R 21 TUNNELLING (January 1969)
R22 8260 R 9 CC=A7200 Electronic transport in condensed
matter
R23 7944 R 19 CC=B2520 Semiconductor theory, materials
& properties
Enter P or PAGE for more |
3. Limit your narrower terms using the /df (descriptor full) index. This looks for the terms as exact phrases rather than searching on the individual terms within them.
|
?s (r1, r3:r12)/df
25685 SEMICONDUCTORS/DF (January 1969)
108630 AMORPHOUS SEMICONDUCTORS:WIDE BAND GAP SEMICON
S3 134105 (R1, R3:R12)/DF |
4. EXPLODE the term using an explanation point at the end of the term.
Note identical retrieval—exploding the term is the same as selecting the term and all narrower terms from the EXPAND list and limiting to the full descriptor (/DF). |
?s semiconductors!
S4 134105 SEMICONDUCTORS! (January 1969) |
RELATED HOW DO I...? SOLUTIONS
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