Today’s post is both a teaching tip and a writing tip.

As a teacher, I often find myself commenting on student papers that something “doesn’t flow.”

As a writer, I also find myself wrestling with flow in my own writing.

And yet, “flow” is one of those infuriatingly vague concepts that can sometimes be hard to teach. But I’ve stumbled across one trick that’s fairly easy to remember and works great to teach students a concrete sense of “flow.”

Here’s the rule:

• Move from “old” to “new” information.

Now some explanation for the rule. Writer’s have an unspoken contract with their readers to lead them in an understandable direction–part of this means making sure readers get the connection between one idea and another. In other words, readers don’t really expect us to take them over the waterfall with no warning.

To do this, it’s often (especially in more essay-style writing) a good idea to start sentences simply, with information that’s already been raised in the paper (the old information). There’s even some scientific research to back up the fact that readers *expect* familiar information in the “topic position” (the first part of a sentence). At the same time, we’ve been trained to expect new and/or significant information in the “stress position” of a sentence (the end of a sentence). Hence the rule–start with familiar information, then move to new information. (For a great, if more technical summary of how this rule can improve scientific writing, see Judith Swan and George Gopen’s “The Science of Scientific Writing.”)

Look at the following examples, from Joseph Williams’ Style.Which of the two “flows” best? 

1. Some astonishing questions about the nature of the universe have been raised by scientists studying black holes in space. The collapse of a dead star into a point perhaps no larger than a marble creates a black hole. So much matter compressed into so little volume changes the fabric of space around it in puzzling ways.
2. Some astonishing questions about the nature of the universe have been raised by scientists studying black holes in space. A black hole is created by the collapse of a dead star into a point perhaps no larger than a marble. So much matter compressed into so little volume changes the fabric of space around it in puzzling ways.

 Most readers will say the second does. And the reason it flows better, is because the second sentence of the second example starts with familiar (old) information–the idea of a black hole raised by the first sentence. In the first example, there’s a sentence length gap between connecting ideas, and readers feel that gap (even if they don’t notice it consciously) as a lack of flow. (When I use this example with students, I also like to point out that the second example uses passive voice to achieve greater flow–in other words, passive voice isn’t always wrong. Like most writing and rhetorical choices, it depends on the situation. If you’re using passive voice for a reason, it’s okay. Then again, this might be a post for another day).


While I wouldn’t claim that this rule has revolutionized my writing or my students’, it has given me a more effective tool for smooth writing. I hope it will do the same for you!