Scientific writing 3.0: A reader and writer's guide - Jean-Luc Lebrun, Justin Lebrun 2021

Non topic-based progression schemes
Set progression tracks for fluid reading
The reading toolkit

Progression through explanation and illustration

The second sentence in the following paragraph introduces a progression of a new type: the explanation.

It usually follows a question or a statement that acts as a question.

Although the new algorithms have worst-case polynomial complexity, in practice they are shown to perform faster than the linear time algorithm. This is because their construction methods have good locality of reference and they have taken the computer’s memory architecture into consideration.⁴

In this example, the first sentence says: the new algorithms should have performed worse than the existing ones, but they outperform them. The reader is intrigued and waiting for an explanation. It comes in the second sentence.

You can also announce the progression with transition words such as for example, similarly, similar to, an analogy for, etc., which prepare an explanation based on a related example, an analogy, or a metaphor. Finally, you can illustrate with visuals. Just write (Figure #)!

What! Metaphors?

These last two chapters seem to discourage calling on the reader’s imagination. One must define ferocity. One must keep the reader on track and channel reader thoughts. Does this mean that, you, the writer scientist, should keep reader imagination at bay because Science is objective? Many examples in this book come from an article written by Professor Wolynes entitled “Landscapes, funnels, glasses, and folding: from metaphor to software”. Rather than trying to convince you, I will quote here the first few sentences of his article. “Of all intellectuals, scientists are the most distrustful of metaphors and images. This, of course, is our tacit acknowledgment of the power of these mental constructs, which shape the questions we ask and the methods we use to answer these questions.”

Time-based progression

Another instance of a non topic-based progression, the time-based progression is commonly found in the methodology section of any scientific paper.

“The protein when it is first made exists in an extraordinarily large variety of shapes, resembling those accessible to a flexible strand of spaghetti. (2) The Brownian motion of the protein strand will carry it willy-nilly between various shapes, somehow finally getting it to settle down into a much less diverse family of shapes, which we call the “native structure” of the protein.”⁵

In this time-based progression, the passage of time is expressed by changes in the verb tenses from the present to the future, and by the adverbs first and finally.

Although words such as first, to start with, then, after, up to now, so far, traditionally, finally, and to finish mark the start, the middle, or the end of a time step, time is often implicit. The reader scientist understands that the writer is following the logic of time when narrating the various steps of an experiment. Most often, the passage of time is established by changing the tense of a verb, from the past to the present, or from the present to the future.

Numerical Progression

The numerical progression is often used when describing a multistep process. It is most clear when the number of steps is announced upfront, allowing the reader to know exactly how far along they are in the process. For example: “Minimizing losses during pulp extraction requires a delicate 6-step process from collection to treatment. Step 1: […] Step 2… etc.

Announced Progression

Progression can be numerical, but it can also follow an order defined by the author (the elements of a list, for example). In the next sentence, the author announces two factors that contribute to the propagation of dengue fever before covering each one in turn.

Two factors contribute to the rapid spread of dengue fever: air transportation, and densely populated areas.

Logical Progression

The progression can follow implicit logic, or explicit logic such as the cause and effect relationship announced by the words thus, therefore, because...

The earnings report revealed a disastrous loss in gross income over the last two quarters. As a result, many employees, even those with seniority, feared for their jobs.

However, beware of logical transitions, as they may sometimes mask knowledge gaps, as in the following example:

In December, the temperature in crowded Cambodian outdoor markets can sometimes drop a few degrees, therefore shopowners drink very little water.

Likely having no experience with Cambodian markets, this logical transition might perplex you. What connection is there between markets, the temperature, and water intake? And yet I can assure you that the sentence above is factual, and would indeed be considered logical to someone more knowledgeable of Cambodia.

This logical transition hides two facts. Firstly, the general knowledge that a drop in temperature can increase the pressure on the bladder, and thus require more frequent trips to the bathroom. And secondly, that bathrooms in Cambodian outdoor markets are rare and/or far, so going to the bathroom would require shop owners to abandom their stalls temporarily. This can be very inconvenient, so shopowners instead reduce their need to go to the bathroom at all… by drinking less water.

Now when you re-read the example above, you no longer have those logical gaps and can make full sense of the sentence. Remember to re-read not only for text fluidity, but for cognitive fluidity.

Progression through transition words

Progression is sometimes announced by transition words, such as in addition, moreover, furthermore, and, also, besides. These linking words are a topic of controversy among people who teach writing. Some say they are just a convenient way to ignore progression; that they artificially establish a link where none exists. Unfortunately, they are often right. I recommend that when you see these transition words, you try to replace them with an implicit progression, such as a sequential step or a topic progression. If you cannot replace them, it may be that an explicit progression using these transition words is necessary, as in this conclusion paragraph:

Our method determined the best terminal group for one specific metal-molecule coupling. In addition, we confirmed that Smith’s formula for calculating molecular binding energy is less computationally intensive and more accurate than the frequently used formula proposed by Brown [8].

The two sentences are independent. ’In addition,’ here, emphasizes the extent of the contribution of the paper.