CHAPTER 4 / CRITICAL READING SKILLS 173
Lesson 2:
Analyzingthe Purpose and Central Idea
Finding the Purpose
About 20–30% of SAT CR questions are “pur-
pose” questions, such as “The overall purpose
of this passage is to... .” or “The author refers
to the ‘mountaintop’ in line 6 in order to em-
phasize... .” These questions ask whythe au-
thor wrote the passage or used a particular
word, phrase, or reference. You will always be
prepared for these questions if you focus on
overall purpose as you read.SAT CR passages are drawn from a wide range of
disciplines, but every passage has only one of three
possible purposes:
- To examine a concept objectively. A passage that
examines a concept is an analysis. It is strictly
informative, like a newspaper article or a textbook
passage. Think of it as a response to an essay ques-
tion. It is objective—sticking to facts rather than
opinions. - To prove a point. A passage that proves a point is
anargument. It presents the author’s point of view
on a topic and explains why it is better than another
point of view. It is subjective—a matter of opinion
rather than fact. - To tell a story. A passage that tells a story is a
narrative—a piece of fiction, a biography, or a
memoir. It describes how a character changes in
order to deal with a conflict or problem.
To understand a passage, begin by asking, “Is
this passage an analysis, an argument,or a
narrative? Is its main purpose to inform to per-
suade, or to inform?” Knowing this makes an-
swering many SAT questions easier.Often, the introduction to the passage gives
you clues about the purpose. Look for key
words such as these:- Analysis key words: examine, analyze, scien-
tific, historical, explore - Argument key words: comment, argue,
opinion, perspective, point of view, position - Narrative key words: biography, story, auto-
biography, memoir, novel, fiction,account
Finding the Central IdeaOften, the first question after an SAT passage
is a “central idea” question such as “With
which of the following statements would the
author most likely agree?” or “This passage is
primarily concerned with... .” Knowing the
central idea is critical to answering these ques-
tions. When you are given two “paired” pas-
sages, it is particularly important to know how
their central ideas compare and contrast.Although SAT passages contain lots of ideas, each
has only onecentral idea. Find it. Every different type
of prose has a different type of central idea.- Every analysis focuses on a questionthat might
interest a college professor. It might answer a
question such as “What methods do scientists use
to measure the location and intensity of earth-
quakes?” or “What were the social conditions of
women in 19th-century England?” - Every argument focuses on a thesis—the point the
writer is trying to make. An argument takes a side and
makes an evaluation. It argues againstsomething
substantial and doesn’t merely support a claim that
everyone already agrees with. Too many students for-
get this. When reading an argument, ask “What sub-
stantial idea is this author arguing against?” - Every narrative focuses on a conflict—the prob-
lem that the main character must deal with. There
is no story without conflict—conflict drives the
story. Basically, every story consists of (1) the intro-
ductionof the conflict, (2) the developmentof the
conflict, and (3) the resolutionof the conflict.
Understanding a story begins with understanding
this structure.
Once you discover the purpose of the passage,
find its central idea—the question, the thesis,
or the conflict. Underline it in the passage or
jot it down in the margin. To make sure that
you really have the central idea, check that it is
supported by everyparagraph. Often, students
mistakenly think that the first idea in the pas-
sage must be the central idea. Not necessarily.
For instance, an author may describe an oppos-
ingviewpoint before presenting his or her
own, so his or her central idea doesn’t appear
until the second or third paragraph.