Chemical Literature (Chem 184/284)

Lecture 2: Techniques of the Efficient Information Searcher

One of the major goals of this course will be to give you the information you need to search thoroughly. You will be introduced to some of the major resources in the chemical literature and how and why to use them. You will also learn the criteria you need to use to evaluate an unfamiliar source.

Step-by-step to Information Searching

• Define what you're looking for; determine what information will satisfy your needs.
• Determine what you already know -- a subject term, an author, a known reference -- that can serve as a starting point for your search.
• Decide which tools can best find answers based on your initial information. What's "best" will vary not only with the problem at hand, but with the available resources at that time and place.
• Find an initial set of "hits", and select the most relevant ones.
• Decide if these answers satisfy your need for information. If not...
• Review those answers for new clues -- terms, authors, cited references, citing references, etc.
• From these, repeat the cycle until satisfied.

Defining the Problem

• Intellectual scope: The needs of researchers for information can range from a single datum, say, the melting point of a known compound, to a comprehensive review of the literature for the best methods for a new synthesis of a complex natural product, to a patentability search which tries to demonstrate that a new invention has never been previously reported in any published literature. The searcher should decide in advance just how comprehensive the search must be.
• Chronological scope: Based on your knowledge of the field, how far back into the published literature will you need to look to satisfy your needs? Research on nanodevices doesn't need to go back more that a few years, for example, but searches for synthetic methods, or natural products, or epidemiological information may need to delve as far back as sources allow.
• Practical considerations: First and foremost, how quickly and how badly do you need an answer? If you need a piece of information RIGHT NOW!, as in, say, information on how to deal with a chemical spill, your approach will probably be significantly different than for a proposal due in three months. Once you've decided how urgent the information need is, the second question is: how much money can you afford to spend on the problem? This will affect not only which tools you have at your disposal, but whether you can get copies of documents you may need, or get translations of materials in languages you don't read. Remember that lack of information can often be more costly than getting the right information in the first place. That's why companies will spend tens of thousands of dollars on patentability searches -- when millions of dollars may hang in the balance depending on what they find.

What is your starting point?

• In any search, you have some starting information which will influence what approach you take.
• At a minimum, you have the terms which you used to define the problem. Most information sources have some way of searching by keyword, or index term. Always remember that there may be synonyms for your terminology, and that you may need to use those in your search as well.
• You may well have additional information in hand at the beginning of your search, such as the name of a key researcher in the field, or a company or educational institution involved in that area. You may know the name of a journal which specializes in that field.
• If you have at least one document in hand that is pertinent to your search, you have a source of numerous possible leads:
  • Its authors may have published additional material on the topic. You can use their names for author searches.
  • The author(s)'s address(es) may point you to other research done at their institution or company. You may even want to contact the author(s) directly and pose your questions to them.
  • The text of the document may yield additional search terms or synonyms for the ones you already have.
  • You can look up the document in an appropriate index, and see if it leads to to search terms used by that database. Patents may yield national or international classification codes which you can use for further searching.
  • Most scholarly papers and patents have a list of references or a bibliography. These can lead you to older, but still relevant documents useful to your search. Some indexes let you find documents which cite some of the same references.
  • You can use the document as a starting point by finding indexes which allow you to locate the more recent papers which cite your starting document.
  • In the chemical literature, you will frequently find relevant chemical names, biosequences (e.g. proteins and polynucleotides), chemical identification numbers, structure diagrams and reaction diagrams. All of these can be starting points for searches in appropriate databases.

Choose the best tools for your search

• Effective searching requires a familiarity with the available search tools, both to select appropriate tools and to use them efficiently once you've chosen them.
• Characteristics of an information resource which may influence your selection include:
  • Availability -- Is the tool "at hand" when you need it? Will you have to pay to use it, and, if so, can you afford it?
  • Ease of use -- Is it a familiar tool? If it's new to you, how easy is it to learn? If it's familiar, is the effort required to use it proportional to the reward of finding the answer you need?
  • Coverage -- Does it cover the type of information you need? The type(s) of documents? The chronological range?
  • Organization -- Does it allow you to search in the way that will answer your questions?
• One of the major objectives of this course is to introduce you to some of the major resources in the chemical sciences which you are likely to use, as well as to the type of analysis you should do when you encounter a new resource.

Search and Select

• With appropriate starting points and tools at hand, you can now take a first stab at researching your topic.
• Always remember that no single search will find every possible reference on a topic (if the topic is at all complex) and that searches will rarely give a set of results without any irrelevant answers.
• There are always trade-offs between getting ALL relevant answers and getting ONLY relevant answers. Information specialists refer to this as the trade-off of comprehensiveness vs. precision, recall vs. relevance or collation vs. specificity
• The more sophisticated your tools are and the more expert your search strategies, the better you will do in achieving both ideals at once...but there will always be some trade-offs.
• Ultimately, you will have to evaluate the answers you find, both to weed out the irrelevant from the relevant, and to decide if you have answered your original question adequately. You may find, in some cases, that your original question wasn't exactly what you needed and need to revise it.

If You're Not Satisfied...

• Assuming that you found at least some useful sources, now examine them for new "clues" to deepen your search. Each source you found will yield more potential starting points for your search.
• In library jargon, this is referred to as pearl-growing. Just as a pearl grows from a grain of sand, with layer after layer of nacre built up until the pearl is harvested, so the searcher can build upon each previous search until the results are suitably valuable. I like to refer to it as the Iterative Approach to literature searching.

Example

Shin-ichi Yoshida, Tsuyoshi Ogiku, Hiroshi Ohmizu,* and Tameo Iwasaki, First Stereocontrolled Syntheses of Unsymmetrically Substituted Bislactone Lignans: Stereocontrolled Syntheses of Four Possible Isomers of Methyl 4,8-Dioxoxanthoxylol
J. Org. Chem., 62 (5), 1310-1316

Let's say you find this article fascinating.

How might you build on the information contained here to find additional relevant information?

Analyze the information contained in the article for pointers that might lead you to more information. [To be discussed in class.]

This page created by Chuck Huber (huber@library.ucsb.edu).
Updated: 12/19/05 02:36:19