Not every heading scheme lends itself to parallel form this extensive, of course. And you don't necessarily want an absolutely rigid scheme of parallel form in every instance. Let's say, for example, that you want to emphasize the different impacts of contaminants on the various Clinch River animals. You may decide to take the parallelism as far as the basic syntax of your headings but vary the descriptive verb in each phrase:

Beavers Decimated by Contaminants
Great Blue Herons Turned Brown by Contaminants
Turtles Shrunk by Contaminants
Fish Deformed by Contaminants

Or, perhaps your document is reporting that the various effects on the animals are being brought about by different kinds of contaminants. Then your headings may become:

Beavers Decimated by Asbestos
Great Blue Herons Turned Brown by Industrial Dyes
Turtles Reduced in Size by PCBs
Fish Deformed by Radionuclides

Sounds like a series of newspaper articles, doesn't it? Nothing wrong with that. Journalists are trained to come up with clear, engaging headings in order to draw readers into the reports they've written. You must learn to do the same. Again, you need not achieve RIGID parallel form among headings, but remember this: some level of parallel form should signal elements that are coordinate.

Let's now consider the operation of that principle at the level of phrases within sentences in the body of your communications.

Parallel Form in Sentences and Phrases
The same principle of parallelism that applies to your headings applies to prose within the body of your text. One way to improve your use of parallel form is to check sentences that list things. If you've written,

Our plans are to consolidate routes, reduce the number of drivers, and we're also planning on upgrading the computer dispatch system,

change it to:
We plan to consolidate routes, reduce the number of drivers, and upgrade the computer dispatch system.

Parallel form is not only easier to read, it reduces ambiguity. Consider the following sentence, which contains three non-parallel phrases:

Villagers can improve community health by learning how to purify water reservoirs, keeping garbage confined to one area, and by cooking all meats thoroughly.

After you've read the sentence, you're left wondering whether the writer really meant to list three separate items, or whether the activity of "keeping garbage confined to one area" is the WAY "to purify water reservoirs."

Assume that we're talking about three separate activities here, and reconstruct the sentence to show parallel form:

Exercise #2
Create parallel form in the following sentences:

To become a scout leader, a parent attends a training weekend to learn scouting fundamentals, or simply by paying dues and attending meetings.

The report considers factors important in choosing an investment, the ratings of companies, and reasons why stocks are better investments than futures.

The Muscle Club offers a variety of services: health checks, spotting your weightlifting, large personal locker, providing towels, machine for spin-drying bathing suits, massages by expert masseuses, and trainers to advise your entire workout.

This last revision takes us to the "next level" in terms of parallel form. Parallel form should exist not only between coordinate items or phrases within a sentence, but also BETWEEN clauses and independent sentences where that form will focus meaning and enhance readability.

Perhaps the easiest place to see this application of parallel form at work is in an "isocolonic" sentence, a sentence with two parallel ideas, holding equal weight, and capable of being neatly split into two separate, parallel sentences. Remember, the parallel nature of the ideas can reinforce or build on each other, as in the examples above, or they can oppose each other:

"It was the best of times; it was the worst of times."

That famous sentence of Dickens's is written in "antithetical" form--just another way of saying parallel but opposing. It could have been written as two distinct sentences, but Dickens wanted the reader to grasp that balanced contradiction as essentially "one thought," so he choose to write that one antithetical sentence. This same technique can be used in professional writing:

Sometimes the data seemed to confirm our hypothesis; sometimes the data seemed to contradict our hypothesis.

Of course, once you get a feel for "balanced thought," you see lots of options with a sentence like this:

• Sometimes the data seemed to confirm our hypothesis, sometimes to contradict our hypothesis.
• The data seemed sometimes to confirm our hypothesis, sometimes to contradict it.
• The data seemed sometimes to confirm, sometimes to contradict our hypothesis.

And so on. Which version is "best"? Sorry. Can't answer that. Depends on what came before, what's coming after, and what you're up to. By the way, notice the parallel form in that list of "depends on" items? Sure you did. Or if you didn't, that's because parallel form, rightly used, takes the reader's mind down a smooth path to understanding; what you'd have noticed is a bumpy departure from parallel form.

The technique of balancing two thoughts within a sentence is a fairly simple one. Let's focus now on the more complex technique of achieving parallel form between sentences in a paragraph.

Exercise #3
Try your hand at improving parallel form between these sentences:

Big convention centers often host several conventions at the same time. You can go in one door and hear a presentation that is really giving Darwin the thumbs down and arguing for an entirely different theory of organic evolution. Another lecture will be going on in another room, this one all about how to invest your money in futures, which will build you a much quicker fortune. Then in a third conference room, an explanation of the very best grooming and handling techniques for poodles that compete in dog shows is being listened to!