Chemical Information Sources/Guides
Introduction: Search Strategies and Guides
A SEARCH STRATEGY is a map of a course of action in searching that ought to result in finding an answer to a chemical information problem. It could involve using library, free internet, and/or commercial database resources. A search strategy includes such tasks as:
- identifying the main concepts and other parameters for the search (time period, types of documents to be retrieved, other factors to be considered, e.g., immediacy of the need for the answer)
- drawing up a list of terms and other search keys to be used (e.g., chemical structures, authors' names, chemical names, etc.)
- deciding what sources are most likely to have the answers
- searching the printed works or databases until the answer is found or you are satisfied that no answer can be found in the available resources.
For the third step, the works described in this chapter will help you make appropriate choices. Works that help you decide what secondary or primary tools to use, or works that actually help you use those tools, are referred to as GUIDES, sometimes called TERTIARY tools. These may help:
- find relevant tools to solve an information problem, and
- learn how to use those tools.
Guides are found as printed books, directories of databases, directories of resources on the Internet, "how-to" manuals that accompany software or databases, and in several other formats, including online help files.
With the proliferation of Web-based resources in recent years, a variety of both free and subscription-based resources are widely available. Academic institutions usually have publicly available guides to both types of resources; however, access to subscription-based resources is limited to those affiliated with said institution. Professional organizations and societies (such as the American Chemical Society or the Royal Society of Chemistry) also have some resources freely available. Private companies often have internal databases and resources, and requisite guides to accompany them. Often, commercial databases will have some documentation publicly available, and more information can often be found in the academic guides as well.
As a part of this work, a guide to chemistry resources on the Internet has been compiled. It is recommended to check with your local institution to see what subscription-based resources are available, and what in-house guides are available. Resources for some Web-based commercial databases are included in the Chemistry Databases on the Web subsection of this work. Finally, chemical information teaching resources are being deposited in XCITR, a cooperative site sponsored by the American and German Chemical Societies and hosted by the Royal Society of Chemistry.
Print guides are still available and may be of use if Web-based guides are insufficient or unavailable. The classic work of this type was Mellon's Chemical Publications which came out in five editions between 1928 and 1982. Much of the printed literature of chemistry may never be available on the Web. A more recent printed guide is Andrew Poss's Library Handbook for Organic Chemists (Chemical Publishing Company, 2000). The "Search Orientation Table" in that work relates questions to appropriate sources. You will find there the tables of contents of standard printed works such as the treatise Comprehensive Organic Chemistry. Here is a link to a list of printed guides in science, technology, and medicine - this link will be moved to this site and edited in the near future.
A searchable guide to both printed and computer-based reference tools is the Chemistry Reference Sources Database (CRSD).
The Difference Between Databases and Vendors / Platforms, and Guides to Using Them
VENDORS are commercial entities that lease database content from DATABASE PRODUCERS and sell access to those files over public or restricted-access communication lines. Increasingly, the mode of delivery is the Internet, and the Web site through which databases are accessed may be referred to as a platform. As such, a database may be licensed to several different vendors, and each may make it available through their own platform. One general example of this would be movie listings - the movie theater or chain would be producing the database of when the movies will be shown, but one could access this information through a variety of platforms, including the movie chain or theater website, a local newspaper (or news website), or Google directly.
Some literature database examples of this include the National Library of Medicine's MEDLINE database, which is accessible through SciFinder, PubMed, and Web of Knowledge platforms. The CAPlus database is available through the SciFinder and STN platforms. It is important to note that the same database may be available on several different vendors' systems, sometimes with different components of the database or different time periods available, and most likely different codes for the various fields of data in the records. Even a single vendor may offer multiple access points to certain databases, some designed for experienced searchers and others, for novices.
A particular type of guide is the DATABASE SUMMARY SHEETS provided by the vendors or producers of online databases. The vendor Dialog Information Services makes available their "bluesheet" database summary sheets. STN's database summary sheets are also available as Internet files. Look at the database summary sheets for the LCA (Chemical Abstracts Learning File on STN) and LREGISTRY (Chemical Abstracts chemical dictionary learning file on STN). Note the different search and display possibilities that are possible with these files and how the summary sheets help you select the right way to enter the search if you were using the native command language of the STN system, STN Messenger. Nowadays, most chemical searchers don't have to know anything about the STN command language because Chemical Abstracts Service's SciFinder product does much of that work for you behind the scenes. Nevertheless, some examples of the STN Messenger command language searches are included throughout this work in order to demonstrate the power of command-language searching. Command line searching on the vendor systems is still very much in demand in industry because it allows experienced online searchers to be much more precise with their search strategies.
Another approach to selecting a database is to let the commercial vendor's search system analyze which databases among their offerings have information relevant to your search. Dialog Information's DIALINDEX identifies which DIALOG files have information on a given topic; INFODEX is an online index to the contents of more than 30 databases on the Chemical Information System, a collection of environmentally-oriented databases. The corresponding type of search on STN would be done with the STNindex feature. The STNGuide file is a database of STN Summary Sheets. It can assist in selecting the proper database to search. Here is a search on STNGUIDE to identify databases that have information on organometallic compounds. The results are brief descriptions of the databases that include organometallic compounds in their coverage.
The literature of chemistry is so huge that it can be a bewildering task to decide just where to start. The guides that have been developed over the years can remove most of the uncertainty about the best path to find an answer to a chemical question. One thing to keep in mind, however, is that some chemical questions will not have answers in the literature. It is up to the searcher to decide how much time and effort should be used in the pursuit of an answer. A well thought-out strategy, based on the information gleaned from the guides (and, if possible, consultation with a local chemical information specialist) can make the search much more fruitful.