May be informative or descriptive.

  • Descriptive (or indicative) abstracts serve as a table of contents for the article but do not summarize it. An example of this less common type may be the abstract scientists provide prior to presentation at a conference.
  • Informative (or summary) abstracts summarize the article. They enable scientists to keep up with the literature without reading entire articles. This is essential in today’s flood of information!!

Informative abstracts mimic the pattern of the full article. For example, if the article follows the IMRaD format, the informative abstract should, too.

  • First sentence(s) = introduction (present tense). State principle objectives and scope of the investigation.
  • Second sentence(s) = methods (past tense). Briefly describe methodology used; include scientific names of organisms studied, names of chemicals, and new terms used.
  • Third sentence(s) = results (past tense). Summarize the results.
  • Fourth sentence(s) = discussion & conclusions (present tense). State main conclusions.

An abstract:

Introduces the content of the paper in a way that helps a reader decide whether or not to read the paper in its entirety.

Appears on its own in abstracting journals (such as Biological Abstracts or Chemical Abstracts) and on-line information services. Abstracts should be self-contained.

Must be less than 250 words (100 words for some journals). Economy of words is essential in abstracts!

Contains familiar language – no jargon! Remember the broad audience for abstracts.

Should be written after the paper. The exception to this rule is the descriptive abstract written prior to a conference presentation. This abstract may even be written prior to the performance of the research!

Does not include references to literature.

Excludes any information not included in the manuscript (such as commentary).

Does not include graphics.

How to write an abstract:

  • Look for a “nugget” sentence in each IMRaD section.
  • If a nugget sentence is absent, summarize each section’s content in a sentence or two.
  • Review your abstract to be sure some vital piece of information has not been omitted.