Appendix D: Writing Comparisons

College classes often ask you to write comparative analyses in which you compare two or more items in a way that offers some meaningful conclusions.  You can compare almost anything – even porcupine and mushrooms – as long as you have a clear reason for your comparison (a thesis) and logical criteria for comparing the items.  For example, although porcupines and mushrooms seem to have very little in common (different life forms) you might compare how both porcupines and mushrooms have developed similar self-preservation methods to avoid predators.  In order to compare two items, they must have obvious differences, but interesting similarities – or, conversely, obvious similarities, but interesting differences.  Your reason for comparing can often be expressed by clearly articulating these interesting similarities or differences.

In technical communication, comparisons are helpful when discussing options, such as in recommendation or problem-solving reports, with a goal of recommending the option that best meets the criteria for resolving a matter. In such documents, options would be compared using the criteria as the basis for comparison with the goal of convincing the reader of the best solution.

This chapter will review

1. the basic grammar of comparative sentence structure, and
2. the overall comparative structures.

1. Comparative Grammar

We frequently engage in making comparisons in daily life. This leads to a sort of “shorthand” in the way we express comparisons. This shorthand might be understood in a conversational way, but in formal writing, we must adhere to certain grammatical standards. A correct comparative sentence should adhere to the following rules:

1. Clearly identify the things being compared.
2. Ensure the compared items are equivalent and comparable.
3. State the specific criteria for comparison.

These rules might seem obvious, but we often break them in our informal conversational comparisons. For example, the following sentence wants to compare the difficulty of dealing with the peels of apples and oranges, but grammatically compares apple peels to “my lab group,” which are not equivalently comparable.

Compared with apple peels, my lab group found orange peels more difficult to deal with.

How would you fix this sentence to correctly express the comparison of apple peels to orange peels?

They say you can’t compare apples and oranges, but you actually can as long as you have established their equivalence, have stated a purpose, and defined clear criteria for comparison.  For example, you CAN compare apples to oranges, but you cannot compare apples to fruit.  You can compare fruit to vegetables, but you cannot compare fruit to carrots.  These are non-equivalent.  Non-equivalent comparisons are often a result of faulty sentence structure.

Here is an example of an effective comparative topic sentence:

There are significant differences between apples and oranges in terms of their culinary uses, nutritional content, and growing needs. 

Comparative sentences can fail for several reasons:

1. They are incomplete (do not clearly identify the two items being compared):
   • Apples grow better in northern climates.
   • Oranges have twice the vitamin C content.
   • Apples are considered more effective “comfort food.”
   • This design is better.
2. They are too vague (they don’t provide enough meaningful information about the items):
   • There were some differences in the characteristics of apples and oranges.
   • There were some similarities in the teamwork between the two labs.
   • Lab 2 was better than lab 1.
3. The comparisons are faulty (often missing information, a sentence structure error, or idiom error):

• • This process of juicing oranges is different than apples.
  • Compared with the first lab exercise, my team and I have a more professional approach toward our common goal.
  • Cooking apples is easier as opposed to oranges.
  • This lab helped us understand the value of teamwork as against individual work.

2. Comparative Structure:  Alternating vs Block Structures

Comparisons are used to compare options in recommendation and other technical reports. Just as there are rules at the sentence level, there are also guidelines for comparative paragraph and report structure. Alternating (also called Point-by-point) and Block (also called Whole-to-whole) structures are common ways of organizing a comparative analysis, and the structure you use will depend on what, how, and why you are comparing.  Let’s say you are writing a comparative analysis of two types of wind turbines. Your overall purpose might be to analyze them to determine which is most economical to operate.

1. Alternating Style arranges the structure based on the criteria for comparison. One criteria might focus on characteristics; the second criteria might focus on performance, while a third might focus on maintenance.
2. Block Style arranges the structure based on the items being compared (each turbine).  Each paragraph will focus on one of the turbine types, and may discuss more than one criteria for comparison.  For example, the first section might focus on one turbine in detail, and might discuss performance and maintenance. The next section would focus on the other turbine, using the same criteria for comparison: performance and maintenance.

Often, Alternating structures work well for this kind of comparison, as you can structure your analysis based on a discussion of each factor in turn. You might choose to organize your analysis in a Block style, if the turbines are quite different and you are focusing on different criteria for comparison for each turbine. The table below shows simplified outlines for each structure:

Table D-1 Simple Outlines of Block and Point-by-Point Structures

Block and Point-by-point structures are helpful principles for organizing your ideas, but keep in mind that you do not have to rigidly follow these outlines. You can mix these up a bit and use hybrid methods.  Examine the excerpt below, from Douglas Rushkoff’s book Program or Be Programmed: Ten Commands for a Digital Age (2011).  Identify where the author has used block style, point-by-point style, and a mixture of the two. Also, note the use of comparative transitional words and phrases (highlighted for emphasis).

References

Rushkoff, D. (2011). Program or be programmed: Ten commands for a digital age. Soft Skull Press, pp. 52-54.