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Search Solution
Using Coding and Indexing to Search Ei Compendex® and INSPEC

Ei Compendex® (File 8/COMP) and INSPEC (File 2/INSP) offer coding and indexing systems that allow more precise searching of the engineering literature. The following search strategies offer techniques for searching classification codes in File 8 and chemical indexing in File 2.

Classification Codes and Headings in File 8/COMP

CAL Classification Codes (CC= on Dialog or .CC. on DataStar) comprise a numeric classification scheme that segments the literature in the database into broad technical subject areas. The scheme consists of over 175 technical disciplines. The present set of codes has been used in Compendex since May 1970. A primary heading is assigned to each document to reflect its main subject emphasis. In addition to the primary term, up to five additional headings or subheading combinations can be assigned. These terms describe additional concepts expressed in the original document and/or expand on the concept represented by the primary term. The number of codes depends on the content of the article. CAL classification codes have three-digit numbers. On Dialog the CAL codes have also been cascaded to the two-digit level, permitting a SELECT of a group of related subject areas with a single entry. For example SELECT CC=66 retrieves all codes from 661 to 664, the codes for Automotive Engineering. (See Figure 1)

On DataStarWeb and DataStar for Windows, handy look-up lists are available so that you can choose the CAL codes most appropriate for your search needs.

How to Use CAL Codes. CAL codes are particularly useful for searching terms in their appropriate context. For example, the phrase Computer Simulation has been used as a main heading or subheading in many different subject areas, so it will retrieve a high number of postings. The search statement in Figure 2 restricts the occurrence of the phrase to records indexed as CC=69, Materials Handling.

CAL codes can also be used to broaden a concept and increase retrieval. In the following search query, retrieval is increased by selecting the CAL code for Coal Mining (CC=503) and then combining terms for coal mining from the Descriptor and Identifier fields. (See Figure 3)

Note: The previous search example retrieves references to coal mine, mines, mined, and mining, but not coal minerals.

On Dialog there are several ways to retrieve CAL Classification Codes:

• CAL classification codes and their corresponding headings may be obtained by EXPANDing in the CC= index (e.g., EXPAND cc=66). (See Figure 4)

• Two- or three-digit codes may be selected directly with the CC= prefix (e.g., SELECT CC=672). The two-digit code, and its corresponding main heading, also display in the record (e.g., CC=672 (NAVAL VESSELS). (See Figure 5)

• CAL Classification Headings (CC=) corresponding to Classification Codes are also searchable with the CC= prefix. Classification headings have been indexed by individual word and by complete phrase in the CC= index. Headings may be selected as single words, using proximity operators, or as complete phrases with the CC= prefix (e.g., SELECT CC= (OCEAN(W) TECHNOLOGY) or SELECT CC= AIR POLLUTION). (See Figure 6)

• Only the first 46 characters of a heading are displayed in an EXPAND list, but the complete heading displays in the record. When lengthy headings are selected as complete phrases, enter the first 46 characters exactly as they appear in the record including exact spacing and punctuation. Truncation may be used with unique word stems (e.g., SELECT CC=MECHANICAL & MISC?). (See Figure 7)

• The (S) operator, which requires that search terms be in the same subfield in any order, is useful for ensuring that all terms appear in the same heading (e.g., SELECT CC=(ACOUSTICAL(S) INSTRUMENT?) (See Figure 8)

• Use the (W) operator to replace punctuation when headings are selected with proximity operators as individual words (e.g., SELECT CC=(OCEAN(2W) TECHNOLOGY).

Note: To search individual words of headings rather than complete phrases requires that you use a proximity operator and enclose the terms in parentheses.

On DataStarWeb and DataStar Windows, use the look-up list.

Chemical Indexing Fields in File 2/INSP

Information about inorganic chemical substances and material systems can be found in INSPEC (File 2/INSP). This information is indexed and searchable using the CI= prefix for all records added to File 2 since January 1987. The chemical indexing fields are structured so that both the substance or substances being searched and their role (e.g., as dopant, substrate, or part of an interface system) can be specified. (Note: Chemical indexing is not used for organic materials because the organic compounds mentioned in INSPEC are typically simple ones, are usually indexed by name (e.g., "anthracene") rather than formula, and occur in contexts that do not involve the complexities of the inorganic systems covered by INSPEC that make chemical indexing useful.)

Searching the CI Field on Dialog

There are different strategies to use to search for chemical substances and compounds.

• For each substance or material system entry in the Chemical Indexing (CI=) field include the substance or system terms and their components down to the level of individual elements.



• Each index term is associated with a role indicator that describes the role played by the material system or element in the format CI=ITEM ROLE, for example, CI=GAAS BIN for gallium arsenide as a binary system.



• Each entry is indexed and searchable both as a complete phrase and using proximity operators (e.g., SELECT CI=GAAS BIN or SELECT CI=(GAAS(W)BIN).



• All indexing terms relating to a particular substance or system are in a single subfield, with each term (item plus role) separated from the next by a space, a hyphen, and another space (e.g., GAAS BIN - GA BIN - AS BIN).

Chemical groups that are recognized for indexing purposes are listed in the Chemical & Numerical Indexing User Manual available from INSPEC. Note: Only records added to INSPEC since February 1987 have chemical indexing (CI=); in earlier references, chemical substances and systems must be searched in the Identifier field.

Searching the CI Paragraph on DataStar

On DataStar when searching chemical indexing on INSP, qualify your search to .CI. (e.g., 1_: GAAS ADJ BIN.CI.) to retrieve gallium arsenide as a binary system.

Classification Codes on INSP on DataStar. Additionally, on DataStarWeb and DataStar for Windows, we have implemented look-up tables giving you access to the full list of INSPEC classification codes. This thorough listing of the subject areas covered by the INSPEC database allows you to search the database in a simple and effective way without having to go through the hard-copy manuals to find the search codes appropriate to your needs.

Simply double click the subject listing appropriate to your area of interest; sub-levels can be cascaded, giving you the ability to select the precise code(s) to maximize precision in searching. (See Figure 9)

Most of the hundreds of technical databases include sophisticated coding and indexing systems. Using these added tools, you can find exactly the chemical substances or topics you are looking for. Take advantage of these features when you search the technical files. For more details and examples on how to use the indexing available in the engineering databases, sign up for the seminar Engineering Information and Techniques on Dialog or download the workbook at http://support.dialog.com/training/.

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