Developing Ideas Through Comparison-Contrast: Study Guide (English Language 4.4)

What comparison-contrast does

Comparison-contrast is a method of development: a common approach a writer uses to build and organise the reasoning of an argument so that the reader can trace it (Topic 3.6). To compare is to look at what two things have in common. To contrast is to look at how they differ. Writers use the method for many purposes: to explain something unfamiliar by setting it beside something familiar, to show that an expected difference is not real, or to make a choice between options.

The framework describes the method in two steps: the writer first presents a category of comparison, then examines the similarities and/or differences between the objects of the comparison. And it adds a rule: when analysing similarities or differences, like categories must be used.

Categories and like categories

A category of comparison is the feature on which two things are compared: cost, speed, safety, reliability, effect on mood. It is the answer to the question, “Compared in what respect?”

The rule of like categories means that each object is measured against the same category. You cannot compare the cost of one thing with the speed of another. It is a common reasoning error and it spoils the evidence.

Category	Object A: bus	Object B: bicycle	Like?
Cost per journey	£1.80	£0.10 for repairs and lights	Yes: cost vs cost
Time for a 5 km journey	25 minutes including waiting	20 minutes	Yes: time vs time
Reliability	Bus can be late	“Fun”	No: reliability vs enjoyment

In the last row the comparison fails because one object is measured by reliability and the other by enjoyment. The writer must either compare both on reliability or both on enjoyment.

The categories should also be relevant to the claim. A comparison of two schools’ building colours says nothing about teaching quality. A good comparison sets up a category that does real work.

Two ways to organise

Point-by-point (alternating). The writer takes one category at a time and shows both objects: “On cost… A is…, B is…; on time… A is…, B is…” The reader sees the objects side by side and the structure makes the like categories obvious.

Block (subject-by-subject). The writer takes one object fully, then the other, covering the same categories in the same order. This lets the reader see each object whole, but the reader has to remember the first when reading the second.

Feature	Point-by-point	Block
Best for	Close comparison on a few categories	Complex objects needing description before comparison
Risk	Can feel choppy if there are many categories	Reader forgets the first block; categories may drift
Tip	Use transitions that name the category	Repeat the same categories in the same order in both blocks

Comparison must lead to a claim

A list of similarities and differences is not an argument. The comparison must show why it matters. After presenting the comparison, the writer should say what it proves, for example: “Taken together, these costs show that the bicycle wins on every measure except weather.” In essay terms, comparison provides evidence, and the writer still owes commentary.

Comparison in a published text

Frederick Douglass, speaking at Rochester on 5 July 1852, builds a contrast out of a single category: the benefits that the Fourth of July is supposed to celebrate.

The sunlight that brought life and healing to you, has brought stripes and death to me.

(Frederick Douglass, “What to the Slave Is the Fourth of July?”, 1852)

The objects of comparison are “you” (his white audience) and “me” (the enslaved). The category is the effect of the nation’s freedom on each. The contrast is made sharper by the parallel structure: “life and healing” is set against “stripes and death”, so each side of the comparison corresponds in grammar and in the kind of thing compared (effects on bodies).

Worked example 1: building a comparison with like categories

Task. A student must argue whether a town should spend its transport budget on a new bus lane or a protected cycle track. (The figures below are invented for the exercise.)

Step 1: Choose the claim. The student decides to argue for the cycle track.

Step 2: Select relevant categories of comparison. Cost to build per kilometre, the number of people each could carry at peak time, and the effect on road safety.

Step 3: Gather like data for each category.

Category	Bus lane	Cycle track
Cost to build, per km	£2.0 million	£0.6 million
Peak-hour capacity, people per hour	4,000	5,000
Recorded injuries on the route, per year after opening (town estimate)	6	2

Step 4: Check for like categories. Each row compares the same feature for both objects. (If the student had compared “cost” for the bus lane with “popularity” for the cycle track, the evidence would not be comparable.)

Step 5: Choose an organisation. Point by point: three categories, each with a short paragraph or a short section, will keep the two options side by side.

Step 6: Draft a paragraph with commentary.

On cost, the cycle track is cheaper by a wide margin: £0.6 million a kilometre against £2.0 million for a bus lane. It also carries more people at peak (5,000 an hour against 4,000), which is surprising given that cycling seems the lesser mode. The reason is that a lane of bicycles uses far less space per person than a lane of buses. A town that can move more people for less money has a straightforward case; the injury figures, 2 a year against 6, only strengthen it.

Step 7: Check that the comparison leads to a claim. The paragraph ends on what the comparison proves, not on a list.

Worked example 2: describing what a comparison does in a text

Read this passage (Marlbridge passage).

A letter and a text message both carry news. But a letter must be composed before it is sent, because it will take days to arrive and cannot be unsent; a text may be sent half-formed because a correction can follow in seconds. The letter-writer therefore edits in advance, and the text-writer edits afterwards. This difference of timing, more than the difference of technology, explains why letters read like speeches and texts read like conversations.

Step 1: Name the category. The category of comparison is when the writer does the editing (timing of revision).

Step 2: Name the objects and the like categories. A letter and a text message. Each is compared on the same category: when revision happens.

Step 3: Say what the comparison does. It begins with a shared feature (“both carry news”), then draws a difference (timing), then uses that difference to explain a conclusion about style.

Step 4: Write the analysis sentence. The writer compares letters and text messages on a single category, the timing of revision, so that a difference in style that might look like a matter of technology is explained as a consequence of how each medium allows a writer to correct mistakes.

Step 5: Check for like categories. Both objects are compared on the same feature. The writer does not slip from timing to length or from timing to formality, which would blur the point.

Common misconceptions

• “Comparison means finding only similarities.” Compare-contrast includes both similarities and differences; the claim decides which to emphasise.
• “Any two features can be compared.” Only like categories give fair evidence.
• “A comparison is an argument by itself.” It is a method of development. A comparison must be tied to a claim by commentary.
• “Block organisation is lazy.” It is a legitimate choice when objects are complex or the reader needs each whole before the comparison.
• “A comparison should include as many categories as possible.” Too many categories make a list. Choose the few that bear on the claim.
• “The two objects must be equal in all respects.” They do not need to be equal; they need to be compared fairly in the chosen category.

Self-assessment: rate your own comparison

Criterion	Not yet	Getting there	Secure
Category	No clear category; features chosen at random	A category is present but not named	The category is named and relevant to the claim
Like categories	Objects measured on different features	Mostly the same feature, with a slip	Every object measured on the same feature throughout
Organisation	Mixed order; reader must hunt for the pairs	Mostly point by point or block, with drift	A consistent pattern with transitions that name the category
Claim	The comparison ends as a list	A claim appears but is not tied to the evidence	The ending states what the comparison proves

Try it yourself

Compare reading a printed book with reading on a screen, on two like categories, in three or four sentences, ending with a claim.

Suggested answer

On eye comfort, a printed page needs no backlight, whereas a screen can be adjusted for brightness and text size, which suits readers who need larger print. On portability, a printed book is one item, whereas a screen can hold hundreds of books in the same bag. Taken together, the comparison shows that the printed page suits a reader who values simplicity, and the screen suits one who values choice and adjustment.

The categories are eye comfort and portability; each object is measured on both; the last sentence states what the comparison shows.

Where this leads

In Topic 4.5 you will look at a different method of development, definition and description. To see how a thesis can signal which methods the body will use, revisit Topic 4.3. Check your learning with the practice questions, the revision notes and the checklist.