Critical thinking involves examining information, evidence and reasoning before reaching a conclusion. It is not the same as being negative or automatically rejecting what other people say.

Define the Question

Start by identifying exactly what you are trying to determine. A vague question can produce a vague answer. Separate what you already know from what you assume and what information is still missing.

Check the Evidence

Ask where a claim came from, whether the source has relevant expertise and whether the evidence actually supports the conclusion. For important claims, compare more than one reliable source and look for the original data or document when possible.

Question Assumptions

An assumption may be reasonable without being proven. Identify the assumptions behind an argument and consider what would happen if one of them were wrong.

Consider Alternative Explanations

A single observation can sometimes support several explanations. Before settling on one, ask what other explanations fit the evidence and what additional information could distinguish between them.

Recognize Bias and Uncertainty

Everyone uses mental shortcuts and can favor information that fits existing beliefs. Being aware of that tendency can improve reasoning, particularly when evaluating emotionally charged, commercial or political claims.

Revise When Evidence Changes

Good critical thinking does not require defending the first conclusion indefinitely. A conclusion should be updated when better evidence becomes available. The aim is not to win every argument but to reach a conclusion that is proportionate to the available evidence.