Reading comprehension question types - Inference questions (...

Learning Outcomes

After reading this article, you will be able to recognise and answer LSAT reading comprehension inference questions. You will know how to distinguish information that is implied or must be true from what is merely stated or could be true. You will be able to explain what constitutes a valid inference, identify common traps in answer choices, and apply elimination strategies to LSAT-style inference questions.

LSAT Syllabus

For LSAT, you are required to understand reading comprehension question types, including inference questions. Emphasis for your revision should be on:

• identifying what is implied in the passage, as opposed to what is merely stated
• distinguishing between must-be-true inferences and weakly-supported possibilities
• using passage evidence to prove your answer, avoiding outside knowledge or speculation
• applying elimination tactics to attractively wrong answer choices

Test Your Knowledge

Attempt these questions before reading this article. If you find some difficult or cannot remember the answers, remember to look more closely at that area during your revision.

1. Which of the following is most likely to be a correct answer to an LSAT inference question?
   1. A statement directly quoted in the passage
   2. A statement strongly implied but not stated
   3. A commonly accepted fact unrelated to the passage
   4. An opinion asserted in the introduction

2. True or false? An answer choice to an inference question must be strictly supported by the passage, even if it is likely or "generally true" in real life.

3. In LSAT inference questions, which answer choice is most likely wrong?
   1. One that generalises beyond the evidence
   2. One that uses cautious language
   3. One that is based on passage logic
   4. One that is a necessary condition from a conditional statement
4. Complete the sentence: If a reading passage says "All flowers in the garden are red," which statement must be true?
   1. Some flowers in the garden are blue
   2. Every flower in the garden is red
   3. The garden contains only red flowers
   4. All red flowers in the world are in the garden

Introduction

Inference questions in the LSAT reading comprehension section test your ability to draw logical conclusions from the information presented in a passage. These questions do not ask for something directly stated, but for what must be true based on what is provided. The correct answer is always a statement that is proven by the passage—never one that merely could be true. This article explains the logic of inference questions, strategies for approaching them, and effective elimination of traps.

Recognising Inference Questions

Inference questions can be identified by stems such as:

• "Which one of the following is most strongly supported by the passage?"
• "Which of the following can be properly inferred from the passage?"
• "It can be logically concluded that..."

These questions demand an answer that is strictly supported by the passage’s content and reasoning.

Key Term: inference
A statement that must logically follow from the facts and reasoning in the passage, even if not directly stated.

Key Term: must be true
A conclusion that is guaranteed by the information or logic presented, leaving no room for reasonable doubt.

Key Term: implied information
Content the author suggests or makes implicitly clear, even though it is not explicitly written.

How to Approach Inference Questions

When faced with an inference question:

1. Read the question carefully. Note any references to specific parts of the passage.
2. Return to the passage. Find section(s) containing the relevant evidence.
3. Determine what is proven. Only accept conclusions that are guaranteed by what is written.
4. Paraphrase the necessary inference in your own words before checking the answer choices.

Worked Example 1.1

Passage excerpt: "Recent studies show that among the city’s birds, only sparrows and finches remain common. Hawks have become extremely rare, and crows have disappeared altogether."

Question: What can be properly inferred about crows in the city?

Answer:
Crows are no longer present in the city. "Disappeared altogether" implies that they are entirely absent.

Common Features of Correct Inference Answers

• The correct answer is never broader in scope than the support in the passage.
• Usually uses moderate language ("some," "at least one," "can," "may not") rather than absolute terms like "always" and "never," unless such certainty is proven by the passage.
• The correct choice can always be justified by direct logical reference to information given—there should never be a need for speculation or outside knowledge.

Revision Tip
When evaluating an answer, ask: "Does the information in the passage force this statement to be true?"

Traps and Elimination

Attractively wrong answers in inference questions commonly fall into these categories:

• Unsupported generalisation: The answer choice uses strong or absolute language ("all," "always," "never") unsupported by the passage.
• Outside knowledge: The answer is true in real life but is not proven by the passage.
• Restatement: The answer copies a sentence from the passage but changes its implications.
• Weak support: The answer could be true, but is not required to be true by the passage.

Worked Example 1.2

Passage excerpt: "Despite a national drought, most local farms reported an average harvest."

Question: What is implied about the local farms’ harvests?

a) All local farms had better than average harvests
b) Local farms were unaffected by the drought
c) Not all local farms had below average harvests
d) National harvests were above average

Answer:
c) Not all local farms had below average harvests. Since "most...reported an average harvest," at least some did not have below average results. This is logically certain.
Exam Warning
Do not choose answers just because they sound likely or reasonable. If you cannot point to passage support, they are likely incorrect.

Must Be True vs. Could Be True

A must-be-true answer follows from the facts and cannot reasonably be false if the passage is accurate. A could-be-true answer is possible, but the passage does not guarantee it.

Worked Example 1.3

Passage excerpt: "All species in the river are fish."

Which statement must be true?

a) There are no birds in the river
b) Many species are fish
c) Every species in the river is a fish
d) There are species in the river other than fish

Answer:
c) Every species in the river is a fish. This is demanded by the passage wording. The rest could be true, but are not necessarily so.

Types of Inferential Reasoning

LSAT inference questions include the following variants:

• Deducing facts based on explicit statements
• Inferring relationships or consequences of a rule
• Identifying what the author’s opinion assumes or implies
• Restating the necessary effect of a conditional ("If A, then B") in the contrapositive

Key Term: contrapositive
The logically equivalent reversal and negation of a conditional statement ("If A, then B" gives "If not B, then not A").

Key Term: scope
The limits of what the information in the passage actually proves—correct inference answers cannot exceed this range.

Inference Question Strategy Summary

• Start with what is proven, not what is plausible.
• Use only the passage (not your own knowledge) for support.
• Be cautious with extreme language—almost always a sign of a wrong answer.

Worked Example 1.4

Passage excerpt: "Most board members support the proposal, but a few objected at the meeting."

Which of the following is a valid inference?

a) The proposal was rejected
b) The majority supports the proposal
c) The objectors outnumbered the supporters
d) All board members were present

Answer:
b) The majority supports the proposal. "Most...support" means a majority. The other answers are not guaranteed.

Key Point Checklist

This article has covered the following key knowledge points:

• Inference questions require answers strictly supported by passage evidence and logic
• Correct inference answers never exceed the scope of what is proven by the passage
• Be wary of answer choices with strong claims or outside factual content
• Process of elimination is essential for ruling out could-be-true but unproven options
• Use paraphrasing and reference back to the text to justify your selection
• Contrapositives are a helpful tool when passage statements are conditional

Key Terms and Concepts

• inference
• must be true
• implied information
• contrapositive
• scope