Definition of instructions
Sets of instructions are the most common kind of technical writing. Instructions are defined as a chronological set of steps in a procedure. They are not always numbered steps, but numbering the steps is highly recommended. Instructions are contrasted with process analyses: instructions use active voice to tell a reader how to do something, while a process analysis describes what other people do and what the results may be. Process analyses may be more like telling a story about people and events, while instructions tend to be more like a series of commands.
Good instructions provide some measure of protection from lawsuits. Instructions should include appropriate warnings about the potential danger a product may present when used improperly.
Organizing the material
The usual recommendations about determining the level of instruction your audience requires apply to procedures. Instructions become very unclear when the writer assumes knowledge that the user does not have. When in doubt, explain more rather than less. Use clear organization to make it easier for a knowledgeable user to skim over familiar material.
As noted above, it is recommended to number the steps in a set of instructions. A simple numbered list is sufficient in many cases. When the instructions are complex, a standard outline structure is recommended. Here are four structures that are recommended as being the "most reliable":
Notes, precautions, cautions, warnings, and danger
Some organizations may use a system of five levels of alerts for the reader. The levels below are presented as a suggestion. The definitions used for the alerts are not universal. Defining these levels for the user may avoid misunderstanding of the intensity and importance of the message.
In addition to this graduated scale of alerts, it is recommended that you associate a visual identifier with each of them, so they will be readily recognized in your documentation.
List of tools and materials
When working with hardware, a list of tools and materials
needed to carry out the instructions is expected, and should precede the
instructions themselves. In the case of unusual or specialized equipment,
illustrations are recommended to make the list clear.
If, for example, the reader must obtain a specific part to repair a device,
a picture of the part, the part number,
and a recommended supplier may all need to be provided.
Video of an installation may help enormously.
When describing a mechanism, the technical writer has some choices in the order of presentation of material. When writing instructions, the steps must be put in chronological order: the order in which they are to be carried out. Instructions written in any other order will be confusing at best, and may cause the reader to damage equipment, or suffer injury.
Instructions are written as commands. They must be clear, detailed, and sequential. Use parallel constructions where possible, to improve instructions. For example, this one does not use parallel construction:
In the example above, the third instruction uses passive voice, and does not deliver on the reader's expectation of a simple instruction. A better way to write this:
This set of instructions uses the same (parallel) word pattern three times. It also includes a reference to the location of the parts to remove. Illustrations of the actions would make the instructions better than just text.