Comparisons and Disjunctions

It is often useful to compare two or more things that are similar in some ways but 
different in others.  For example, per Aristotle's topoi a comparison can take the 
following forms:

a) Similarity:  What is the object of comparison similar to?
b) Difference: How is the object of comparison different from similar things?
c) Degree:  What things does the object of comparison differ from only in degree?

In writing a comparison-and-contrast paragraph, try to avoid jumping  back and forth 
from one alternative to another.  Suppose, for example, you are comparing authors X 
and Y are using issues A, B, C and D to compare them; suppose further that the first 
three issues relate to author X and the fourth relates to Y.  In such a case, you should 
present the comparison in terms of these two issue groupings:  first A through C, then 
D.  This will make it easier for the reader to see that Author X  relates to three of the 
four issues and that author Y relates to only one.

Characteristic features of comparison-and-contrast paragraphs include: 

*connective words and phrases:  however, on the other hand, conversely, similarly, 
likewise, in contrast to

* comparative constructions:  more than, -er, than, less than, as. . . as, rather than, is 
different from

*verb tense differences:  Program X will be easy to implement, whereas program Y 
would entail a number of complications

*subordinate clauses:  while, whereas, but

*parallelism:  Model X is reliable and efficient, whereas Model Y is unreliable and 
relatively inefficient...

One final principle of comparison-and-contrast writing is this:  phrase your 
descriptions in such a way that the reader can immediately see how they bear on the 
argument you are making.  In other words, do not routinely make "neutral " statements 
of comparison.  For example, rather than saying, "Item X weighs 3.2 pounds and item Y 
weighs 2.5 pounds," consider saying, "Item X weighs 3.2 pounds whereas item Y only 
weighs 2.5 pounds."   In many cases, using subordinators like whereas and only can 
serve to emphasize the point you are arguing.


Comparisons and Disjunctions