by Professor Merrill Whitburn
In the course of developing a report, essay, memo, etc. writers are often called
upon to define their terms. Some of the more common definitional techniques
used in professional and academic writing are described below.
; An Aristotelian or formal definition assigns a thing to a genus or class
and then indicates the differences between the thing and other
members of the class. Example: Craps is a gambling game played with
two dice in which a first throw of 7 or 11 wins the bet; a first throw of 2, 3,
or 12 loses; and a first throw of any other number (a point) must be
repeated to win before a 7 is thrown--otherwise, the player loses both
the bet and the dice.
; An explication defines the meaning of key words in an Aristotelian or
formal definition. An example that might follow the above definition:
Dice are small cubes marked on each side with a number of small dots,
varying from 1 to 6. The number of dots on opposite sides always add
up to 7.
; An operational definition refers individuals to a location or situation
where they might observe a phenomenon. Example: If you are driving
south along a highway, you will experience the Doppler effect if you
listen to the sound of a car heading north that approaches and then
; An analysis separates a whole into its component parts. Example: Air
is a colorless, odorless, tasteless, gaseous mixture containing nitrogen,
oxygen, carbon dioxide, neon, and helium.
; An example suggests one member of a class of objects to convey an
accurate impression of the entire class. Example: The maple is an
example of a deciduous tree.
; Graphics provide a pictorial representation where lines, dots, arrows,
etc. are configured into representational patterns.
; Comparisons and contrasts suggest ways in which objects or
concepts are similar to or different from one another. Example: Both the
maple and the pine are trees; but the former is deciduous, the latter
; An elimination indicates what something is not to clarify what it is.
Example: Clear-cutting is not the removal of only a few trees in a forest
; An etymology explores the origin and historical development of a word.
Example: Synchronism can be better understood if we realize that the
original meaning of syn was together, and that of chronism was time.
; History records the events in the development of something. Example:
It will be easier to understand what is meant by the discipline of
technical communication if we explore how it evolved.