Evaluating the Strength of Evidence

LNAT passages present a wide range of evidence to support their conclusions — from rigorous scientific studies to personal anecdotes, from government statistics to opinion surveys. Not all evidence is created equal. This lesson teaches you to evaluate the strength, reliability, and relevance of different types of evidence, a skill that underpins many LNAT Section A questions.

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The Three Dimensions of Evidence Quality

When evaluating any piece of evidence, consider three key dimensions:

Dimension	Question to ask	What strong evidence looks like
Reliability	Can this evidence be trusted?	Large sample, rigorous methodology, independent source
Relevance	Does this evidence relate to the specific conclusion?	Directly addresses the claim, not tangentially related
Sufficiency	Is there enough evidence to support the conclusion?	Multiple independent sources, comprehensive data

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Strong vs Weak Evidence

Strong Evidence