SAT Writing: Relevance and Purpose


While the past few chapters dealt with questions that test you on relevance implicitly—after all, topic sentences, transitions, and supporting details all have to be relevant to the passage in context—you'll encounter quite a few questions that test you on relevance explicitly, as well as questions that test you on both relevance and purpose, in other words, how something is relevant. Not only will you have to figure out which answer fits the best, you'll also have to know why it fits.

On the SAT, these questions look like the following:

  • Which choice provides the most relevant detail?
  • The writer is considering deleting the underlined sentence. Should the writer do this?
  • The writer is considering deleting the underlined sentence. Should the sentence be kept or deleted?
  • At this point, the writer is considering adding the following sentence. ... Should the writer make this addition here?
  • The writer is considering revising the underlined portion of the sentence to read.... Should the writer add this information here?

A full example might look like this:

At this point, the writer is considering adding the following sentence:

Joe then confronted Jane about the money she owed him.

Should the writer make this addition?

A) Yes, because the information clarifies Joe's reasoning for his actions.
B) Yes, because the information helps explain how Joe and Jane originally met.
C) No, because the additional information distracts from the main point of the passage.
D) No, because it's unclear whether Joe wanted to argue with Jane.

When tackling these types of questions, always answer the yes or no part first. Is it relevant? Should it be added or deleted? Yes or no? Don't even read the rest of the words in the answer choices. In your mind, just answer yes or no. That way, you've halved the number of choices under consideration. Usually it's pretty obvious whether a sentence is relevant.

Only after you have answered yes or no should you think about the why (why or why shouldn't the sentence be added?). The reason for doing this is to prevent the answer choices from influencing your reasoning, because once you answer yes or no, you instinctively develop your own reason which you can then compare with the two remaining answer choices. Letting the reason you thought up yourself guide you to the correct answer choice is extremely effective—your instincts are often right. Reading the full answer choices before you've had time to think for yourself has a way of playing with your mind.

If your reason doesn't line up with the reasons in the two remaining answer choices, it's a sign you need to reconsider the yes or no part.

Most irrelevant sentences come in the form of random facts that come out of nowhere. Here are some examples (irrelevant parts are italicized):

  • Last Monday, I went to my high school reunion. I was excited about meeting old acquaintances and friends. Afterwards, I went back home with my wife. I had lost touch with them after so many years.
  • My dad runs a bakery in Boston's Chinatown, but there's also a Chinatown in Toronto. He sells freshly baked pork buns, egg tarts, and cakes to the locals everyday.
  • Because All the King's Men was released as a movie before I could read the book, which is often available in used book stores, I decided to watch the movie first. I wish I hadn't though because the book turned out to be far more entertaining.
  • Since its inception, Cathay Pacific airlines has served millions of customers worldwide. Obviously, flying is faster than driving. The company continues to offer world class service, comfortable seating, and delicious meals on all flights.

The best way to spot irrelevance is to evaluate the key words in the sentence in question. If those key words aren't referred to in some way in the previous sentence or the following sentence, chances are that it's irrelevant. Notice in the respective examples above that:

  • There is no reference to home or wife in the surrounding sentences.
  • There is no reference to Toronto in the surrounding sentences.
  • There is no reference to used book stores in the surrounding sentences.
  • There is no reference to driving in the surrounding sentences.

Also notice how the italicized portions interrupt the flow of the passage; they are abrupt shifts in topic. Relevant content will stay on topic; irrelevant content will not.

Another sign that something is irrelevant is a sudden shift in scope—how general or specific something is. The last example above starts out by talking about one specific airline, Cathay Pacific, but all of a sudden, it jumps into something extremely general, that flying is faster than driving. Be wary of these sudden shifts in scope.

At the end of the day, there is no magic formula for determining whether something is relevant. After lots of practice, your intuition will be your best guide.


Ok, so now you've determined whether something is relevant or not. More often than not, you'll have to know why.

Here are some typical reasons for adding/not deleting something:

  • because it provides specific examples of...
  • because it defines a term that is important to the passage
  • because it provides a detail that supports the main topic of the paragraph
  • because it helps explain why...
  • because it provides context for...
  • because it provides support for the claim made in the previous sentence
  • because it establishes the relationship between...
  • because it elaborates on...
  • because it provides a logical introduction to the paragraph
  • because it serves as a transitional point in the paragraph
  • because it adds a relevant research finding
  • because it introduces a new idea that will become important later in the passage
  • because it acknowledges a common counterargument to the passage's central claim
  • because it sets up the main topic of the paragraph that follows

Here are some typical reasons for not adding/deleting something:

  • because it blurs the paragraph's main focus with a loosely related detail
  • because it blurs the paragraph's main focus by introducing a new idea that goes unexplained
  • because it interrupts the flow of the sentence by supplying irrelevant information
  • because it provides background information that is irrelevant to the paragraph
  • because it interrupts the paragraph's description of...
  • because it interrupts the discussion of...
  • because it fails to support the main argument of the passage
  • because it repeats information that has been previously provided
  • because it introduces a term that has not been defined in the passage
  • because it would be better placed elsewhere in the passage
  • because it makes a claim about... that is not supported by the passage
  • because it does not provide a transition from the previous paragraph
  • because it does not logically follow from the previous paragraph
  • because it contradicts the claim made in the previous paragraph
  • because it contradicts the passage's claim about...

You don't need to memorize any of these. Just familiarize yourself with them.

The most common reason by far for not adding/deleting something is irrelevance. If the question asks whether to add a given sentence and your answer is no, the reason will likely be that it blurs the paragraph's main focus or supplies irrelevant information, so gravitate towards that answer choice first.
The three most common reasons for adding something are defining a term, offering specific examples, and adding supporting detail to a claim. As you go through practice questions, familiarize yourself with what these questions and answers actually look like so that you develop an intuition for how they're tested.

When you encounter purpose questions, always read the surrounding sentences and determine what function the given sentence plays. If possible, try to make this determination before you actually read the answer choices. The purpose of a given sentence or phrase will usually fall under one of the following categories:

  • an explanation of a certain term or phenomenon
  • further description
  • introduction of a topic
  • emphasis of a previous point
  • effective transition
  • specific evidence or supporting detail
  • conclusion of a paragraph or passage

Again, there is no magic formula for consistently determining what the purpose of a sentence is. A lot of it comes down to logic and judgment, which is best improved through practice.

  1. With the idea of a "global village" is fast becoming a reality in the 21st century, it is vital that we enlarge our worldview and understand the cultures of other nations. Influenced by our environment, we are raised with a certain perception of the world around us. █ Very soon, our perceptions, which allow us to make sense of reality and shape it, become fixed, invisible, and unconscious; they become part of our worldview, which, as unique as we might think it is, rests on the shared values of a particular linguistic community.

    The writer is considering adding the following sentence.

    We develop our thoughts and interpretations through the education we have, the news we watch, and the friends we make.

    Should the writer make this addition?

    A) Yes, because it reinforces the point that our thoughts are shaped by external forces.
    B) Yes, because it acknowledges that education is important in society.
    C) No, because it blurs the focus of the paragraph with a loosely related detail.
    D) No, because it contradicts the main idea of the paragraph.

  2. As years pass, the standard of living is constantly being improved due to technological advancements. Even the life span of humans has increased now that medicine and research are readily available. However, developed biomedical methods such as cloning are controversial, and in fact, 93% of all Americans oppose cloning. █ Because of the controversies surrounding this practice, the United States has refused to open the door to reproductive cloning. This decision lead to a debate among government officials, scientists and bioethicists. Although the critics of human cloning fear that this biomedical practice would create an unpleasant environment that contradicts religious aspects and beliefs, cloning can help infertile women reproduce, cure diseases, and restore the sanctity of life.

    The writer is considering adding the following sentence.

    Cloning is already used agriculturally to produce fruits and vegetables of higher quality.

    Should the writer make this addition?

    A) Yes, because it explains why cloning is so controversial among Americans.
    B) Yes, because it supports the paragraph's point that cloning can be beneficial.
    C) No, because it doesn't acknowledge any health risks that may be associated with cloned food.
    D) No, because it detracts from the paragraph's focus on cloning humans.

  3. To expand on just one benefit, cloning would allow people with fatal injuries to obtain the necessary organs needed for their recovery. Many people are put on a waiting list today because there aren't enough donors. Blood types and other characteristics must match before organs can be transferred. Even then, unexpected incompatibilities may exist, resulting in further medical problems. Antibodies provided by the new organ may not cooperate with other cells in the patient's immune system. Cloning organs would ensure that the replacement is both identical and compatible.

    The writer is considering deleting the underlined sentence. Should the writer make this deletion?

    A) Yes, because it interrupts the discussion by introducing a detail that goes unexplained.
    B) Yes, because it contradicts the main point of the paragraph.
    C) No, because it provides a specific example to support the previous sentence.
    D) No, because it illustrates one of the reasons cloning is so controversial.

  4. After professionals have mastered different major roles in society and can perform their tasks flawlessly, they are capable of teaching others the same knowledge. In other words, they have enough experience in a certain profession to teach others how to do things properly. Professionals, however, are still students. The world today is constantly changing and bringing new challenges to every industry. Old practices may easily become extinct, forcing people to shift their perspectives on many social issues.

    Which choice provides the most relevant detail?

    B) migrate to new locations in search of work.
    C) work together in ways they haven't before.
    D) learn new skills and adapt them in innovative ways.

  5. Though hypnosis is often dismissed as a playful trick used by magicians, it can actually increase a patient's focus and alleviate a wide range of mental issues when used in a serious manner. For example, many people have successfully cured their phobias through hypnosis, whether it be a fear of flying or a fear of water. Others have used it to recover suppressed memories or alter destructive habits such as overeating and smoking. It can have a significant effect even after just one session with a trained hypnotherapist. While the science behind it remains dubious, there is no question that some people have had dramatic results. Hypnosis, if performed by a competent practitioner, has the potential to reshape the mind to create new responses, feelings, behaviors, and thoughts.

    At this point, the writer wants to reinforce the point that hypnosis has many applications. Given that all of the choices are true, which one best accomplishes this goal?

    B) instill motivation in athletes and put insomniacs to sleep.
    C) bring about some detrimental side effects, however.
    D) lead to a number of short and long-term benefits.

  1. A
  2. D
  3. C
  4. D
  5. B