Technical descriptions are similar to technical definitions. but technical descriptions can be stand-alone documents, whereas technical definitions are always components of a larger document. Furthermore, technical descriptions

• are usually longer than technical definitions,
• contain more detail,
• focus on functionality,
• often describe complicated subjects with multiple parts, and
• contain technical definitions.

Technical Description Parts

Since technical descriptions are longer and more detailed than technical definitions, descriptions contain two major sections: Introductions and Body sections.

Introduction

The contents of a technical description’s introduction are very similar to the contents of a formal letter. In the first paragraph, you need to

• identify the thing to be described;
• provide some basic background information (purpose of writing, context of writing);
• give a brief overview of the thing to be described (what is it like, what is its purpose); and
• preview the rest of the document.

Body

After the Introduction, a technical description’s content will vary, depending on your audience and the thing being described. However, there are a few common themes in any technical description’s body paragraphs.

Background

The body paragraphs flesh out the background information in more detail. Again, like the body of a formal letter contains details about the letter’s subject, the body of a technical description contains details about the background of the thing being documented. Of course, tailor the content based on your audience and the subject at hand.

Technical Description Organization

Long technical definitions need their own organization strategies, just as any piece of writing does, but technical descriptions usually rely on one of three organization schemes:

• general-to-specific
• spatial
• chronological

Your choice of an organization strategy will depend on the kind of thing you’re describing. In general, you’ll always want to go from general to specific, for you need to begin by defining the thing and then proceed by breaking it down thematically. What that theme is, though, depends on the nature of the thing being described.

General-to-Specific

For example, let’s say you’re documenting a bicycle. Would it do any good to just start naming pieces? “Okay…here’s the front wheel, and here’s the seat, and here’s the handlebars…ooh! My favorite part, the chain guard!” Of course not; you need some sort of internal logic to the parts list. A logical scheme might be to begin with major systems—frame, wheels, gears, brakes—and then describe how the systems work together or go into more detail about the parts that compose each of these systems.

Spatial

What about describing the construction of a four-barrel carburetor? You’d likely want to describe how the parts fit together, so a spatial organization scheme would make sense, complete with an exploded-view diagram of the  parts. (As a completely irrelevant side note, in the year 2000, I met the inventor of the four-barrel carburetor; he was in his early nineties, and he was volunteering as a math tutor at a community college in Arizona. He was a very nice fellow.)

Chronological

But what about describing a process, like smelting iron? Giving a tour of the factory wouldn’t make much sense, would it? “Here’s the blast furnace, and over here is the rock crusher. And then on this side, we’ve got the mold-making shop and a pile of spare wheelbarrow tires.”

No…you’d want to proceed chronologically, step-by-step, through the process. “First, dump trucks haul in raw ore and pour it into this bin. Then we use a bucket loader to transfer the ore into this machine, where we pulverize it. Then we load the crushed ore into these crucibles and roast the ore until the iron melts out. From that point, we…” You get the idea.