Biotechnology: Searching effectively

Provides information and selected resources relevant to biotechnology

Steps for effective database searching

Plan and execute an effective search using the following six steps. The screen shots are from the Ovid Medline database, but the process is applicable to database searching in general.

  1. What is the topic?
    Example: What effect does vitamin E have on cardiovascular diseases in the elderly?
  2. What are the key concepts?
    • vitamin E
    • cardiovascular diseases
    • elderly
  3. Are there other ways to express these key concepts, in order to widen the search?
    some general examples:
    • synonyms (including American terminology) eg heart diseases, cardiac diseases
    • plural / singular eg. woman, women
    • spelling variations eg behaviour, behavior
    • variations of a root word eg strategy, strategic
    • acronyms eg CVD, cardiovascular diseases
  4. For each key concept, join its keywords with OR
    • vitamin E or alpha-tocopherol
    • cardiovascular diseases or CVD
    • elderly
  5. Link each key concept set with AND, to obtain records which contain at least one of the terms from each concept set:
    (vitamin E or alpha-tocopherol or alpha tocopherol) and (cardiac diseases or heart diseases) and (elderly)

While the effect of OR is to widen the search, AND narrows or focuses the search. You may see them referred to as Boolean operators in search guides.

This is how the example search is entered in the Scopus database:

Scopus database search boxes

Evaluate the records retrieved, and modify the search accordingly
From the results list view the records which seem to be the most relevant.

Look for new search terms within the results, especially in the abstract or subject terms, which you can use to refine the initial search.

Further tips for modifying a search

To focus the initial search:

  • reduce the terms linked by OR
  • add another key concept, linked by AND
  • limit by date range

To widen the initial search:

  • increase the terms linked by OR (refer to Step 3)
  • remove a key concept
  • use the truncation symbol (see below).


Typing a truncation symbol after the root of a word will find variations of that word. This can be a powerful way of expanding the search. The truncation symbol is often a star or asterisk (*). For a particular database check the online help to confirm the symbol to use. For example:

  • behavio* will find behavior, behaviour, behavioral, behavioural...
  • child* will find child, childhood, children...