Online Technical Writing:
Abstracts



An abstract is a summary of a body of information. Sometimes, abstracts are in fact called summaries--sometimes, executive summaries or executive abstracts. There are different kinds of abstracts—your technical report uses two types: the descriptive abstract and the informative abstract.

Note: Students enrolled in the Online Technical Writing are encouraged to take the reading quiz on this chapter. (Anybody else is welcome to try it as well.)

Descriptive Abstracts

The descriptive abstract provides a description of the report's main topic and purpose as well an overview of its contents. As you can see from the example in Figure 1, it is very short—usually a brief one- or two-sentence paragraph. In this report design, it appears on the title page. You may have noticed something similar to this type of abstract at the beginning of journal articles.

In this type of abstract, you don't summarize any of the facts or conclusions of the report. The descriptive abstract does not say something like this:

Problem:  Based on an exhaustive review of currently available 
          products, this report concludes that none of the 
          available grammar-checking software products provides any 
          useful function to writers.

This is the style of summarizing you find in the informative abstract. Instead, the descriptive abstract says something like this:

Revision: This report provides conclusions and recommendations on 
          the grammar-checking software that is currently 
          available.

The descriptive abstract is little like a program teaser. Or, to use a different analogy, it like major first-level headings of the table of contents have been rewritten in paragraph format.

Figure 1. Descriptive abstract on report title page.

Informative Abstracts

The informative abstract, as its name implies, provides information from the body of the report—specifically, the key facts and conclusions. To put it another way, this type of abstract summarizes the key information from every major section in the body of the report.

It is as if someone had taken a yellow marker and highlighted all the key points in the body of the report then vaccuumed them up into a one- or two-page document. (Of course, then some editing and rewriting would be necessary to make the abstract readable.) Specifically, the requirements for the informative abstract are as follows:

This last point is particularly important. People often confuse the kinds of writing expected in descriptive and informative abstracts. Study the difference between the informative and descriptive phrasing in the following examples:

Informative:  Based on an exhaustive review of currently 
              available products, this report concludes that 
              none of the available grammar-checking software 
              products provides any useful function to writers.

Descriptive:  This report provides conclusions and recommendations
              on the grammar-checking software that is currently 
              available.

                            ABSTRACT


     Computerized speech recognition takes advantage of the most
     natural form of communication, the human voice. During
     speech, sound is generated by the vo cal cords and by air
     rushing from the lungs. If the vocal cords vibrate, a voiced
     sound is produced; otherwise, the sound is unvoiced. The
     main problem in speech recognition is that no two voices
     produce their sounds alike and that an individual voice va-
     ries in different conditions. Because voices do vary and
     because words blend together in a continuous stream in
     natural speech, most recognition systems require that each
     speaker train the machine to his or her voice and that words
     have at least one-tenth of a second pause between them. Such
     a system is called an isolated word recognition system and
     con sists of three major components that process human
     speech: (1) the preprocessor which removes irregula rities
     from the speech signal and then breaks it up into parts; (2)
     the feature extractor which extracts 32 key features from
     the signal; and (3) the classification phase which
     identifies the spoken word and includes the training mode
     and reference pattern memory. Spoken words are identified on
     the basis of a certain decision algorithm, some of which
     involve dynamic programming, zero crossing rate, linear pre-
     dictive coding, and the use of state diagram.
     
     Voice recognition systems offer many applications including
     data entry, freedom for mobility, security uses, telephone
     access, and helpful devices for the handicapped. However,
     these same systems also face problems such as poor
     recognition accuracy, loss of privacy among those who use
     them, and limited vocabulary sizes. The goal of the
     industry is the development of speaker-independent systems
     that can recognize continuous human speech regardless of
     the speaker and that can continually improve their vo-
     cabulary size and recognition accuracy.

Figure 2. Informative abstract—this type summarizes the key facts and conclusions in the body of the report. (By the way, speech recognition has come a long way since this report was written in 1982!)

Revision Checklist for Abstracts

As you reread and revise your abstracts, watch out for problems such as the following:

Return to the table of contents for the Online Technical Writing Course Guide (the online textbook for online technical communication courses at Austin Community College and other institutions worldwide).
This information is provided and maintained by David A. McMurrey. For information on use, customization, or copies, e-mail hcexres@io.com.