Lecture Notes— Definitions and Descriptions

DEFINITIONS clarify a description of new developments or technologies in discrete fields (e.g., new name and species description). They help specialists communicate with general readers. Writing definitions depends on the writing situation, the kind of definition needed, and the appropriate place for the definition.

WRITING SITUATION begins with AUDIENCE and PURPOSE (duh!). Technically astute audiences need less, general readers need more.

KINDS OF DEFINITIONS include short or long, informal or formal, in three types:

• PARENTHETICAL—brief, in an existing sentence (usually a word or phrase). These serve as quick introductions to new terms.
• SENTENCE—a one-sentence clarification. Pattern is to place item in a category of similar items and then distinguish it from them. Sentence definitions may assign a local meaning (…”in this paper…”) to a term.
  • Be specific in stating the category and the distinguishing characteristics.
  • Don’t describe a specific item if you are defining a general class of items.
  • Don’t be circular, repeating the key words or characteristics being defined.
  • Include a noun in the category (don’t substitute “when, what, or where.”)
• EXTENDED—detailed, usually one or more paragraphs, description of an object, process, or idea. Techniques used include (depending on audience and purpose)
  1. Graphics. Draw a picture, then explain it.
  2. Examples. Clear sentence with abstract term, followed by examples of specific instances.
  3. Partition. Divide a thing or and idea into smaller parts, each of which is more easily understood.
  4. Principle of Operation. Tell how something works.
  5. Compare and Contrast. Describe similarities and differences between what is being defined and a more familiar item that the reader understands.
  6. Analogy. Compare one item to one that is completely different in some ways, but the same in some essential characteristic. (CPU compared to brain.)
  7. Negation. State what the item is not before describing what it is.
  8. Etymology. Definition based on the origin of a word. (e.g., spam, output, SCUBA, etc.)
  9. History of the term. Explains the original use of the term and subsequent changes in meaning.

PLACING THE DEFINITION (except for parenthetical, which go within the sentence, of course) typically involves six locations

1. In the text.
2. In the marginal gloss (in the margin, next to the text).
3. In a hyperlink (web).
4. In footnotes (on same page or at the end of the document).
5. In a glossary (alphabetized list of definitions).
6. In an appendix.

Role of Descriptions.

• Objects—specific sites, phenomenon, artifacts.
• Mechanisms—object made up of identifiable parts that work together, as a machine.
• Processes—Activity that takes place over time, in steps. Process definitions explain how something happens, but are not a set of instructions about how to do something.

Audience and Purpose. Before writing a description, consider the audience, its needs and background (why do they need a description and what should they already know?), and your purpose in writing the description (what do you expect the audience to do with it?)

Suggestions for Writing the Description.

• Indicate the Nature and Scope of the Description (title? section heading? Object, Mechanism, Process?)
• Introduce Clearly. What should you ask in introducing a definition or description? Examples: What is the item? What is its function. What does it look like? How does it work? What are its parts? What is the process/function/order of the process? Who performs the process?
• Provide appropriate detail. Organize using function or physical characteristics of objects, chronology or causal relationships of processes.
• Conclude well. Summarize.