Mechanism Description

Description of a tool, machine, or other mechanical device—usually with moving parts—designed to perform a specific kind of work

Examples: ballpoint pen, flush toilet, copy machine, press, radio, camera, etc.

Process/Procedure Description

Description of an unvarying series of events producing a predictable outcome

Process—a natural phenomenon governed by physical lawsProcedure—events that occur under human control

Examples:

Process—photosynthesis, erosion, water cycle

Procedure—balancing a checkbook, operating a machine, purifying water, taking a temperature, filing a grievance

Instructions

Explanation of how to perform a particular procedure, enabling a reader to duplicate a process

Example: computer manuals, assembly instructions, policy manual

Discussion

Why are technical descriptions and instructions particularly important in our time? New Technologies Changing Technologies More Red Tape

Mechanism Descriptions

General Description—description accurate with respect to all such mechanisms, regardless of variablesSpecific Description—description accurate for one particular mechanism

Examples: camera, Nikon One Touch Zoom ballpoint pen, Ajax Super Ballpoint

Sony Z-16 Color TV, television

Components

Brief introduction defining mechanism and its purposePrecise description of appearanceList of major partsExplanation of how mechanism worksOne or more visuals (esp. exploded, cutaway)Conclusion (history, availability, manufacturer, cost, etc.)List of outside sources

Order of Description

Top to bottom, or bottom to topLeft to right, or right to leftInside to outside, or outside to insideMost important to least important, or least important to most important

Other Guidelines

Use specific, concrete wording Piece of paper vs. 8.5 by 11-inch

piece of paper Colorful vs. red, hard lead vs. 2h lead

Use present tense, active verbs The machine stamps. . . vs. The

machine stamped OR The parts are stamped by the machine

Add evaluative comments The quick release reduces change time

by 33%. The most useful feature is the cancel

option.

Use analogy (comparison) A-frame, C-clamp, T-square, claw

hammer . . . a disk about the size of a typical CD

Instructions

General Instructions—instructions that explain how to perform a generic procedure

Specific Instructions—instructions that explain how to perform a procedure under conditions involving particular equipment, surroundings, or other variables

Examples:

Trimming a hedge, using a Black & Decker Auto Shop electric hedge trimmerBraking a vehicle, braking in wet conditionsInstalling an electrical outlet, installing a GFCI outlet

ComponentsBrief introduction explaining the purpose and importance of the procedureList of materials, equipment, tools, and skills requiredActual instructions: numbered, step-by-step, detailed explanation of how to performOne or more visuals for clarificationBrief conclusionList of outside sources, if any

Guidelines

Use short, simple commands; start with a verb Separate steps unless closely related or simultaneousIf important, provide reason for stepInclude WARNING, CAUTION, and NOTE Warning—alerts to possible injury or death Caution—alerts to possible equipment damage Note—alerts to information that will make the

procedure easier or more efficient

If necessary, use separate series of steps.

Include no more than 9 steps in a series.

Provide introduction/transition to each series.