How to Improve Comprehension of Scientific Writing

The previous series of posts has focused on what features of scientific writing interfere with reader comprehension and how we can change our writing habits to better meet reader expectations.  These ideas are taken from the paper, "The Science of Scientific Writing", by Gopen and Swan (199).

In this post, I will show how Gopen and Swan revised the previous writing example to improve comprehension.  The writing principle we are considering requires that for each sentence, a backward linkage is made to "old information" and new information is positioned for contextualization forward.  The first step is to identify the new material in each sentence that should be emphasized.  I've highlighted these phrases in yellow:

Large earthquakes along a given fault segment do not occur at random intervals because it takes time to accumulate the strain energy for the rupture. The rates at which tectonic plates move and accumulate strain at their boundaries are approximately uniform. Therefore, in first approximation, one may expect that large ruptures of the same fault segment will occur at approximately constant time intervals. If subsequent main shocks have different amounts of slip across the fault, then the recurrence time may vary, and the basic idea of periodic mainshocks must be modified. For great plate boundary ruptures the length and slip often vary by a factor of 2. Along the southern segment of the San Andreas fault the recurrence interval is 145 years with variations of several decades. The smaller the standard deviation of the average recurrence interval, the more specific could be the long term prediction of a future mainshock. 

What needs to be done for each sentence is listed below:

   1. The backward-linking old information appears in the topic position.
   2. The person, thing or concept whose story it is appears in the topic position.
   3. The new, emphasis-worthy information appears in the stress position. 



Here is the revision suggested by Gopen and Swan based on the above guidelines, with the new information (in the stress position) highlighted in yellow and the old information (backward linkage) highlighted in pink:

Large earthquakes along a given fault segment do not occur at random intervals because it takes time to accumulate the strain energy for the rupture. The rates at which tectonic plates move and accumulate strain at their boundaries are roughly uniform. Therefore, nearly constant time intervals (at first approximation) would be expected between large ruptures of the same fault segment. [However?], the recurrence time may vary; the basic idea of periodic mainshocks may need to be modified if subsequent mainshocks have different amounts of slip across the fault. [Indeed?], the length and slip of great plate boundary ruptures often vary by a factor of 2. [For example?], the recurrence intervals along the southern segment of the San Andreas fault is 145 years with variations of several decades. The smaller the standard deviation of the average recurrence interval, the more specific could be the long term prediction of a future mainshock. 

So, how did you do?  Check out Isabella's version of this paragraph--I find hers easier to understand than Gopen and Swan's revision.  Her revision is written in simple, straightforward language and only needs a bit of polishing.  Here is my modification to her version:

Earthquakes occur when a certain amount of strain caused by the movement of tectonic plates has been accumulated. The rates of these movements at the boundaries of tectonic plates are roughly uniform, leading to the expectation that large earthquakes along a given fault segment occur at nearly constant and nonrandom time intervals (at first approximation), because it takes time to accumulate the strain energy for the rupture. However, if subsequent main shocks have different amounts of slip across the fault, then the recurrence time may vary, and the basic idea of periodic mainshocks must be modified.  For great plate boundary ruptures, the length and slip often vary by a factor of 2, resulting in a large standard deviation of the average recurrence interval, which leads to a less specific long-term prediction of a future mainshock. For example, along the southern segment of the San Andreas fault the recurrence interval is 145 years with variations of several decades.

Gopen and Swan state that in their experience, "the misplacement of old and new information turns out to be the No. 1 problem in American professional writing today."

The fourth principle can be stated as:

Place appropriate "old information" (material already stated in the discourse) in the topic position for linkage backward and contextualization forward. 

I find this principle the most difficult one to apply routinely to my writing because as a writer I am anxious to get my idea (the new stuff) down before I forget my brilliant thought.  Consequently, the temptation is to rush the new information and forget to provide backward linking and context for it.  However, by doing this we only address our needs, not the needs of the reader.