Sunday, December 13, 2009

Reader Eggspectations

This post continues the series on principles of scientific writing as described by Gopen and Swan (1990).   We are now at the fifth principle, which deals with verbs (again).  The following is an example given by Gopen and Swan.

See if you can figure out the problem.

Transcription of the 5S RNA genes in the egg extract is TFIIIA-dependent. This is surprising, because the concentration of TFIIIA is the same as in the oocyte nuclear extract. The other transcription factors and RNA polymerase III are presumed to be in excess over available TFIIIA, because tRNA genes are transcribed in the egg extract. The addition of egg extract to the oocyte nuclear extract has two effects on transcription efficiency. First, there is a general inhibition of transcription that can be alleviated in part by supplementation with high concentrations of RNA polymerase III.  Second, egg extract destabilizes transcription complexes formed with oocyte but not somatic 5S RNA genes.

If you've been following along, you should be able to identify some of the problems with this passage.  However, one of the main problems here is that the topics are apparent, but not what they are supposed to be doing.  Readers expect the action of a sentence to be articulated by the verb.  This passage violates that expectation.

Here are the verbs from that paragraph:

     are presumed to be
     are transcribed
     is...can be alleviated

Just looking at this list, we recognize that the passage tells us very little about what actions are actually taking place.

Here is the revision with the new verbs highlighted:

In the egg extract, the availability of TFIIIA limits transcription of the 5S RNA genes. This is surprising because the same concentration of TFIIIA does not limit transcription in the oocyte nuclear extract. In the egg extract, transcription is not limited by RNA polymerase or other factors because transcription of tRNA genes indicates that these factors are in excess over available TFIIIA. When added to the nuclear extract, the egg extract affected the efficiency of transcription in two ways. First, it inhibited transcription generally; this inhibition could be alleviated in part by supplementing the mixture with high concentrations of RNA polymerase III. Second, the egg extract destabilized transcription complexes formed by oocyte but not by somatic 5S genes.

This revision does not fix all the problems, but goes a long way toward improving comprehension.  The verbs are now telling us something about what actions were taken in this study.  Without knowing more about the topic and what the authors were really trying to get across, it's difficult to do more with it.  However, it serves to illustrate the fifth principle:

Articulate the action of every clause or sentence in its verb.

1 comment:

Tsu Dho Nimh said...

Yes, make the verbs do some work for a change!

Great series BTW, I'll be linking to it.