Investigators found heavy mercury concentrations while sampling sediments downstream from our site.

Trauma surgeons recommend lots of things to reduce injuries due to auto accidents, but in first place is shoulder-harness seat belts, which are very effective and are now standard equipment on most vehicles.

A radical new investment strategy that could affect the company's future throughout the 21st century may emerge from these studies, if we take them as seriously as they deserve to be taken, in my opinion.

If sensing devices are not protected from potential part dislocations, severe damage to the machine could result.

Good. Now let's move on up to transitions between sentences in paragraphs. Every sentence in your prose should have some kind of glue attaching it to what has come before.

Transitions
Probably the most obvious action you can take to improve a document's coherence is to make sure you've used enough of those sentences, phrases, and words that show how pieces of text are related. We call these "transitions" because they take you from one conceptual place to another. Transitions should provide coherence on every level of the document. Between major and minor sections, transitions might require whole sentences or even paragraphs; between smaller blocks of text they may be no more than a word or phrase. Sometimes, these are simply pronouns harking back to antecedents (such as "he" pointing back to "Fred"), or repeated words or phrases that connect one sentence to another. For example, let's add a sentence to one of our example sentences from exercise #1:

While sampling sediments downstream from our site, investigators found heavy mercury concentrations. Such dense concentrations of contaminants are common within reservation boundaries, but to find them so far out from the reservation is quite alarming.

However, we can't use that method alone, sentence after sentence, without running the risk of "free association":

Sheep overgrazing is a major cause of soil erosion. Erosion of that kind can turn a beautiful, vegetated hill into a wasteland of gullies. Gullies, once they are deep, can't easily be crossed by motor vehicles. Those motor vehicles, especially ATVs, are turning our once-peaceful national parks and forests into noisy vacation lands for the rich. The rich are really taking over our park lands in every way, not only invading it with all kind of motorized contraptions, but buying up land right next to and even inside of our traditional recreation areas. Recreation is a right of all Americans, and those healthy enough to get out into the wilds should get out there and enjoy it as often as possible.

Such a paragraph is fragmented chatter; the fact that each sentence is linked to the one before it does not, by itself, give the paragraph structure, "architecture." That's why you were taught, in Freshman Composition (and earlier) to create a topic sentence for each of your paragraphs, and then to provide a logical development for your assertion. That development can take many forms, and the topic sentence itself usually suggests a form for development.For example, here's a topic sentence and a schematic for possible development:

Blue whales are bigger, smarter, and tougher than any terrestrial behemoth ever was.

BWs weigh up to 1,500 tons;
--Heaviest dino weighed less than 100 tons.

BWs have Volkswagen-sized brains and enjoy complex inter-whale communication;
--Biggest dino brain was only coconut sized, not capable of complex communication

BWs endure tremendous changes in temperature and pressure
--Dinos were wimps, wiped out by cold weather

The obvious pattern that suggested itself here was comparison and contrast. If you are like most writers in government, industry, and business, you don't have a great deal of trouble perceiving patterns for development of your prose. What you may not be so good at is revealing those logical relationships to your readers, clearly and consistently. You are very close to your own material; you already understand it. Nothing you are writing about strikes you as new or unfamiliar; you already understand the relationships between the ideas in your prose. What you must bear constantly in mind is the fact that your readers will not instantly see all these logical relationships in your prose unless you signal them. If your readers already understood everything in your communication, they'd have no need to read it in the first place.

Here's a good way to test the "coherence factor" of your own prose. Read through a few pages of your writing and circle in pencil all the pronouns that have clear antecedents and all the words/phrases that have a clear repetition or link (some variation of the word or phrase). Draw an arrow from pronoun to antecedent and from words/phrases to their repetitions and links. Then take a pen and draw a box around all the explicit logical connectives such as "moreover," "as a result," "similarly," "later," and "nonetheless." You should end up with a good peppering of boxes; I can't tell you exactly how many. Those logical connectors are what your English teachers keep calling "transitions."

You probably remember those lists of transitions from your undergraduate grammar/mechanics handbook. What you may have forgotten is the great range of logical functions that transitions can serve--or more likely, you have learned a style of professional writing that leaves out many transitions in favor of a "straightforward" style that doesn't "insult the intelligence of the reader." That's generally a cop-out. A transition-poor style of writing is difficult to read, because you've left it to the reader to figure out the relationships between things. Even if your paragraphs have some good internal structure, your reader still feels that you have "data dumped."

Which of these two paragraphs would you prefer to read?

• The contractor is still operating in two shifts. Cleared debris is now being piled. No burning at all is being permitted. The continued dry weather has produced extreme fire hazard conditions. No power equipment is permitted to operate when the relative humidity is below 20%.
  
  
• The contractor is still operating in two shifts, and cleared debris is now being piled. Even so, no burning at all is being permitted, since the continued dry weather has produced extreme fire hazard conditions. Not only is burning prohibited, but no power equipment is permitted to operate when the relative humidity is below 20%.

There's an adage among good writers: "The harder it is to write, the easier it is to read--and vice-versa." If you make your reader do mental work that you should have done, you won't have a happy reader.

Here, for your review, are some common transitional words and phrases, grouped according to function.

Adding
and, also, again, further, furthermore, moreover, in addition, another reason, what's more, equally important

Placing in Time
First (ly), second (ly), later, previously, afterwards, next, and then, formerly, finally, at length, immediately thereafter, as soon as

Placing in Space
here, nearby, behind, next to, futher on, further back, opposite to, in the distance, above, close by

Contrasting
but, yet, still, even so, notwithstanding, nevertheless, on the other hand, despite the fact that, conversely, on the contrary, be that as it may, whereas

Illustrating/Specifying
for example, that is, for instance, in other words, as an illustration, a case in point, namely, the point is, of these, specifically, to demonstrate, for instance

Showing Similarity
in like manner, in the same way, similarly, likewise, also, too, accordingly

Revealing Cause & Effect
due to, since, so, consequently, therefore, thus, hence, then, as a result, we see that, because of this, whereupon

Conceding/Qualifying
though, even though, although, granted, granted that, while, it may be true that, at the same time, doubtless, in spite of, I admit, naturally, up to a point, sometimes

Concluding
in conclusion, to sum up, in other words, finally, in short, in brief, in the last analysis

Revealing purpose
To this end, with this object, because, for this purpose

Note that these are just a few of the sense-making signposts good writers provide for readers. In fact, they are often just the front end of a transition; "notwithstanding" expands to "notwithstanding yesterday's events," and so on.

You should be able to think of other categories of transition. For example, what about the very activity I discussed at the beginning of this unit: "being emphatic"? Although emphasis is best achieved structurally, as I've explained, one may also use transitional words and phrases that specifically convey emphasis:

Emphasizing
Indeed, in fact, as a matter of fact, even, obviously, especially, most importantly, above all, in particular, remarkably

Try your hand at using transitional words and phrases to signal logical connectivity in the following paragraph. Remember, you're free to use your entire kit of stylistic tools.

Exercise #2
Type a transition-rich rewrite into the box below this paragraph:

A Knoxville firm is currently advertising what it calls Automated Homes. These homes are not a new concept. They were first built in Silicon Valley. They would be new to Knoxville. Most residents of Knoxville would have to be educated about just how such homes operate. Robots don't walk around from room to room serving food and picking up dirty clothes in Automated Homes. The robots are the basic appliances and other technologies that most of us are familiar with. These include telephones, microwave ovens, lights, toilets, locks on doors, etc. They are specially designed or adapted. They are run by a powerful, voice-sensitive computer. The computer is the main thing that makes the home Automated, not the appliances and other devices.

Exercise #3
Type another transition-rich rewrite into the box below this paragraph:

The case that market-driven approaches to environmental protection present an attractive alternative to command-and-control approaches has been made frequently by economists in recent years. The use of information as a tool to achieve environmental enhancement has not been much discussed. Approaches that rely upon the dissemination of information to the public have been proliferating at an unprecedented rate. The basic belief is that information will bring about a public response expressed either in the market place or in the political arena. Environmental improvement will come about when an educated public demands it.