When Should You Use Definitions?

• When technical information originally written for expert readers is revised for nonexpert readers.

• When readers from many disciplines or varied backgrounds must understand the document.

• When using new or rare terms.

• When a term has multiple meanings.

Consider Your Subject, Purpose, and Audience When Writing

DefinitionsSubject• What kinds of information are needed to write an accurate

definition of this term?• What information does your reader need to know to understand

the term?• What information is not within the scope of your subject?Purpose• Why you are defining this term?• Are you offering a new definition of this term?• Are you trying to distinguish your definition of the term from

other definitions?• Are you striving for a certain level of accuracy?Audience• Level of expertise?• Why are they reading this document?

Parenthetical/Synonymous

• The leaching field (sievelike drainage area) requires crushed stone.

• The trees on the site are mostly deciduous (shedding foliage at season’s end).

Term Category Distinguishing FeaturesAn ace is a tennis serve that is successful because the

opponent cannot reach the ball to return it.

Term Category Distinguishing Features

A firearm is a weapon from which a bullet or shell is discharged by gunpowder.

A rifle is a firearm with spiral grooves in the inner surface of the gun barrel to give the bullet a rotary motion and increase its accuracy.

A Winchester

is a rifle first made about 1866, with a tubular magazine under the barrel that allows the user to fire a number of bullets without reloading.

Rule: Do not use the same key word in the distinguishing features part that you used in one or both of the other two units

• Poor: A pump is a machine or device that pumps gas or liquid to a new level or position.

• Better: A pump is a machine or device that raises or moves gas or liquid to a new level or position.

• An odometer is a measuring instrument that measures the distance traveled by a vehicle.

• An odometer is a measuring instrument that measures the distance traveled by a vehicle.

• An odometer is a measuring instrument that records the distance traveled by a vehicle.

Rule: Do not use distinguishing features that are too general to adequately specify the meaning of the term

• Poor: Rugby is a sport that involves rough contact among players as they try to send a ball over the opponent’s goal lines.

• Better: Rugby is a team sport that involves 13 to 15 players on each side who try to send a ball across the opponent’s goal line during two 40-minute halves.

• A staple is a short piece of wire that is bent so as to hold papers together.

• A staple is a short piece of wire that is bent so as to hold papers together.

• A staple is a short piece of wire that is bent so both ends pierce several papers and fold inward, binding the papers together.

Rule: Do not use distinguishing features that are too restrictive

• Poor: A tent is a portable shelter made of beige canvas in the shape of a pyramid, supported by poles.

• Better: A tent is a portable shelter made of animal skins or a sturdy fabric and supported by poles.

• An mp3 player is a digital music player that stores and plays mp3 files, video files, text files, and is made by Apple.

• An mp3 player is a digital music player than stores and plays mp3 files, video files, text files, and is made by Apple.

• An mp3 player is a digital music player that stores and plays mp3 files and may also be capable of storing and playing back other file types.

Rule: Do not use is when, is where, or is what in place of the group part (genus) of a formal definition

• Poor: A tongue depressor is what medial personnel use to hold down a patient’s tongue during a throat examination.

• Better: A tongue depressor is a flat, thin, wooden stick used by medical personnel to hold down a patient’s tongue during a throat examination.

• Genetic engineering is when scientists change the hereditary code on an organism’s DNA.

• Genetic engineering is when scientists change the hereditary code on an organism’s DNA.

• Genetic engineering is the set of biochemical techniques used by scientists to move fragments from the genes of one organism to the chromosomes of another to change the hereditary code on the DNA of the second organism.

Rule: Do not use an explanation that obscures your meaning

• Poor: A tumor is a neoplasm

• Better: A tumor is a growth of cells that occurs independently of surrounding tissue and serves no useful function.

• A solenoid is an inductance coil that serves as a tractive electromagnet. (note: okay for an engineering manual)

• A solenoid is an inductance coil that serves as a tractive electromagnet. (note: okay for an engineering manual)

• A solenoid is a coil that converts electrical energy to magnetic energy capable of performing mechanical functions.

Negation

• Raw data is not “information”; data becomes information only after it has been evaluated, interpreted, and applied.

Stipulation

• In this paper, I use the word “affordances” to mean the actions available from the user interface.

Analogy

• Doing distance running is like giving your body a bigger gas tank, and doing speedwork enables your body to work more efficiently, as if you were getting more miles to the gallon.

Illustration

Etymology

• “Biological control” of insects, for example, is derived from the Greek “bio,” meaning “life” or “living organism” and the Latin “contra,” meaning “against” or “opposite.”

History

• The idea of lasers dates back as far as 212 B.C., when Archimedes used a magnifying glass to set fire to Roman ships during the siege of Syracuse.

Examples

• Lasers are increasingly used to treat health problems; for examples, cataracts and detached retinas are now treated with laser surgery.

Operating Principle

• A clinical thermometer works on the principle of heat expansion: as the temperature of the bulb increases, the mercury inside expands, forcing a mercury thread up into the hollow stem.

Analysis of Parts

• Psychoanalysis is an analytic and therapeutic technique consisting of four parts: (1) free association, (2) dream interpretation, (3) analysis of repression and resistance, and (4) analysis of transference.

Comparison and contrast

• A pair of optical fibers has the capacity to carry more than 10,000 times as many signals as conventional copper cable. A ½- inch optical cable can carry as much information as a copper cable as thick as a person’s arm.

All Together Now• Think of a technical term that could require

definition and use the whiteboard space to type your term.

• We’ll create a formal definition of the term together.

• We’ll also create an extended definition (historical, etymological, by part, compare/contrast, negation, by operating principle, by example, by analogy, by illustration, by stipulation).

Technical DescriptionsTechnical descriptions are usually a

description of one of the following:

• An object (aka a product)

• A process

Technical descriptions describe either what something is (exactly), or how something works.

Observational Strategies

• Do background research

• Use your senses

• Take measurements

• Describe motion and change

• Describe the context

• Collect visuals

• Ask subject matter experts

Organizational Strategies• Spatial

– What does it look like?– What parts and material is it made of?– Use to describe what something looks like

• Functional– How does it work?– Use to describe a mechanism in action

• Chronological– How is it put together?– How does it happen?– Use to describe an item best visualized in terms of its

order of assembly

Which organizational strategy would seem to work best?

• A 15-passenger van’s cruise control system

• A digital camera

• A bag of Cheetos

• A piece of furniture from Ikea

Use concrete details and precise and informative

languageSubjective: adorably cute

Objective: resembles a cartoon cow wearing a pink ruffled skirt

Indefinite: a sleek-looking Web server

Definite: the Hush Mini PC

How to organize an object description

• Introduction– Include a formal definition of the object– Define the scope and purpose of the document

• Description and Function of Parts– Organized spatially, functionally, or

chronologically– Proceeds by part one, part two, part three . . .

• Summary and Operating Description– Bring the parts back together in a brief recapping

summary and explain how the object’s design reinforces its use

How to organize a process description

• Introduction– Include a formal definition of the process– Define the scope and purpose of the document

• Brief Description/Overview– Provide a concise overview of the process– Provide background information – Conclude by breaking the process up into its parts

• Step-by-step description– Define the step– State its purpose– Define and describe substeps– Proceed from step one to step two to step three . . .

• Summary– Include a complete cycle of the process and remind the

reader of the process’s end result

Remember the difference between a process description and instructions:– A process description informs the reader, but

doesn’t provide the reader with enough or the kind of information that would enable to reader to actually do the process. Someone reads a process description to learn.

– Instructions tell the reader how to do something. Someone reads a process description to do.

Examples of IntroductionsThroughout the ages, mankind has found many uses for salt.  Ancient tribes

used it preserve meat; around the world it adds flavor to food; the Bible uses it as a symbol of zest for life.  Salt became such an important part of people's diet that a way was needed to allow early nomads to carry salt with them on their perilous travels; such a device ideally also helped ancient gormandizers to distribute portions of the precious flavor enhancer onto their foods.  Thus was born the salt shaker.

This document provides the manufacturing specifications for the entire line of Happy Homemaker "Praying Cow" salt shakers (Divine Bovine Industries model #00045).  A hand-painted ceramic collector's item, the "Praying Cow" salt shaker represents a plump, cartoon-like cow, her head bowed as if in prayer.  A blue flower-print skirt is painted onto the body of the animal.  The salt is dispensed through the cow's matching bonnet, via a circular array of six small holes.  The bonnet twists off to allow the consumer to fill the dispenser cavity. 

Examples of IntroductionsOne of the greatest environmental threats to our nation's

agriculture is the growing acid rain problem. 

Acid rain is one of the greatest environmental threats to our nation's agriculture.

Acid rain is an environmentally harmful precipitation that forms after the combustion of fossil fuels releases nitrogen and sulfur oxides into the atmosphere. This document describes the process in general terms, in order to demonstrate the necessity for increased government regulation in sensitive areas. This paper cites recent studies by Smith and Jones (1997, 1998) to assist EPA officials with their efforts to determine which parts of the country should be designated "at risk" or "potentially at risk" over the next five years.

Object Description, Process Description or Instructions?

• How a thunderstorm forms

• An HP Deskjet 3845

• How an HP Deskjet 3845 works

• How a bill becomes a law

• How to write legislation

• MSU’s campus

• How to change a flat tire

• Creating bassoon reed blanks

All Together Now• Think of an object or a process that could

require a description and use the whiteboard space to type the name of your object or process.

• We’ll work together to figure out how to organize a document that would describe that process or object.

Examples

Rayovac Workhorse Flashlighthttp://www.io.com/~hcexres/tcm1603/acchtml/descx1.html

Interplak Home Plaque Removal Instrumenthttp://www.io.com/~hcexres/tcm1603/acchtml/descx2.html

OSHA Technical Manual on Oil Refining Processes

http://www.osha.gov/dts/osta/otm/otm_iv/otm_iv_2.html

Technical Description of PowerChute Network Shutdown’s Communication Process

http://www.apcmedia.com/salestools/TDOY-5UQVBV_R1_EN.pdf