Compare and contrast

By understanding similarities and differences between two things, we can increase our understanding and learn more about both. This usually involves a process of analysis, in which we compare the specific parts as well as the whole. Comparison may also be a preliminary stage of evaluation. For example, by comparing specific aspects of A and B, we can decide which is more useful or valuable. Many paragraphs whose function is to compare or contrast will begin with an introductory sentence expressed in general terms.

Introducing differences

X is different from Y in a number of respects.
X differs from Y in a number of important ways.
There are a number of important differences between X and Y.
Areas where significant differences have been found include X and Y.
In contrast to earlier findings, however, no evidence of X was detected.
A descriptive case study differs from an exploratory study in that it uses …
Smith (2015) found dramatic differences in the rate of decline of X between Y and Z.
Women and men differ not only in physical attributes but also in the way in which they …
The nervous systems of Xs are significantly different from those of Ys in several key respects.


Smith (2015) found
only slight
differences between X and Y.
Introducing similarities

Both X and Y share a number of key features.
There are a number of similarities between X and Y.
The effects of X on human health are similar to those of Y.
Both X and Y generally take place in a ‘safe environment’.
These results are similar to those reported by (Smith et al. 1999).
This definition is similar to that found in (Smith, 2001) who writes:
The return rate is similar to that of comparable studies (e.g. Smith et al. 1999).
The approach used in this investigation is similar to that used by other researchers.
Studies have compared Xs in humans and animals and found that they are essentially identical.


The mode of processing used by the right brain is similar to that
is comparable to that
is comparable in complexity to that
used by the left brain.
Comparing within one sentence
Oral societies tend to be more concerned with the present whereas while literate societies have a very definite awareness of the past.
Whereas While oral societies tend to be more concerned with the present, literate societies have a very definite awareness of the past.
This interpretation differs from that
contrasts with that
is different from that
of Smith and Jones (2004) who argue that ….
In contrast to oral communities, it is very difficult to get away from calendar time in literate societies.
Compared with people in oral cultures, people in literate cultures organise their lives around clocks and calendars.
Comparing within one sentence: comparative forms

In the trial, women made more/fewer errors than men.
Women tend to have greater/less verbal fluency than men.
Women are more/less likely than men to perform well in tests.
Women are more/less accurate in tests of target-directed motor skills.
Women tend to perform better/worse than men on tests of perceptual speed.
Women are faster/slower than men at certain precision manual tasks, such as …
Women are more/less likely to suffer from X when the front part of the brain is damaged.
The part of the brain connecting the two hemispheres may be more/less extensive in women.

Indicating difference across two sentences
It is very difficult to get away from calendar time in literate societies. By contrast,
In contrast,
On the other hand,
many people in oral communities have little idea of the calendar year of their birth.
Indicating similarity across two sentences
Young children learning their first language need simplified input. Similarly,


In the same way,

low level adult learners need graded input supplied in most cases by a teacher.


Smith (2015) sees X as …

Smith (2015) argues that …



In the same way,

Jones (2019) asserts that …

Jones (2019) holds the view that …