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Writing in Chemistry - Oakland Campus: Search Tips

Selecting Keywords

The search terms or keywords you use to search are what determine the results you get. Here's a good exercise to help you generate keywords:

1. Express your topic in a topic sentence:  "How are residual pharmaceuticals in the water supply measured?"

2. Generate keyword search terms by identifying the main ideas or concepts within the topic sentence: "How are residual pharmaceuticals in the water supply measured?"  --> pharmaceuticals, water supply, measured

3. Expand your search terms by brainstorming related terms or synonyms that describe your main ideas:

  • Pharmaceuticals; drugs, antibiotics, endocrine disruptors, steroids, erythromycin, codeine
  • Water supply; water, drinking water, river, lake, stream, reservoir
  • Measured; analyzed, analysis, determination, detection, detected

Natural Language Searching

Some databases allow you to enter your search in terms and phrases almost as you would speak to another person, called "natural language" searching. The computer then analyzes the search statement, divides it into search terms, and searches the terms all according to pre-defined rules.

SciFinder is a natural language database, and entering your search can be different than in other databases.

  • Identify the major ideas or concepts in your question
  • Express each concept in words or phrases of no more than three words
  • Link synonyms or related terms for one concept using or

Different concepts can be linked in different ways.

  • Enter one concept or set of related terms, search, and refine the results by adding another concept
  • Combine different concepts expressed as single words or phrases using and:                     analysis and pharmaceuticals and water supply    
  • Combine different concepts expressed as single words or phrases using prepositions:                               analysis of pharmaceuticals in the water supply

: If one of your concepts consists of several terms linked by or, (for example, ketones or aldehydes or esters) you should use the first method and enter one concept and then refine the search results with a second concept.

Searching Techniques

Article databases, online library catalogs, and many popular search engines share several general searching techniques. Once you master these common searching techniques, you will save yourself time and find more relevant results.

Combining Search Terms

You can create complex search strategies by combining keywords using the linking words AND, OR and NOT. For example, if your search terms are semiconductor and conductivity:

  • AND - Narrows and focuses the search results. The search semiconductor and conductivity finds only results containing both the terms semiconductor and conductivity.
  • OR - Broadens the search results. Searching semiconductor or conductivity will find results containing the term semiconductor or the term conductivity or both terms in the same result.
  • NOT - Excludes any result containing the term listed after the not.  The search semiconductor not conductivity will find results containing the term semiconductor but not containing the term conductivityUse not cautiously since it excludes all mentions of the term in every context.


Searching the root of a word without specifying a particular ending is one way to find variations on a word that relate to the same core concept without searching each word separately.

Some databases automatically search terms for singular, plural, and various other endings.

Some databases use a truncation symbol to indicate that any ending is acceptable after exactly matching the letters entered.

  • spectro*       will find    spectroscopy, spectroscopic, spectroscope, spectrometer                               but not     spectrum, spectra, or spectral                                              
  • analy*            will find    analyze, analyzed, analysis, analytical, analyte, analytics

The actual symbol used will vary among databases. The asterisk (*) is most common, but some use a ? or other symbol, so check your database.

Note: The SciFinder database does not use truncation. It automatically searches for words with variant endings and, in some cases, for common synonyms.


Phrase Searching

Searching for exact phrases instead of individual words can focus your search so that more results are directly relevant to your topic. Different databases and search engines accomplish this in different ways. Two common ones are:

  • Quotation marks - Some databases treat words enclosed within quotation marks as phrases. Searching "platinum metal catalyst" will find only results containing those three words next to each other in that order.
  • Default setting - In some databases, words typed next to each other are automatically searched as an exact phrase. Searching platinum metal catalyst will only find results containing that exact phrase

Remember: Exact phrase searches can focus your results, but they can also miss some relevant results. Searching the phrase "platinum metal catalyst" will not find platinum catalyst, Pt catalyst, or elemental platinum catalyst, all of which are relevant.


The SciFinder database does not use quotation marks to designate phrases. Enter and search the phrase; then select the answer set that contains terms "as entered" from the list of search results.

Field Searching

In some databases you can restrict searching your terms to specific sections or fields in a database record, for example the article title or author name.

You can tailor your search by combining information from different parts of the record, like combining an author name with a subject term, or focus your search by restricting terms to an article title or abstract.

This is frequently done by using a pull-down menu to select the appropriate field for each search term.