Scepticism is a vital skill that helps journalists uncover the truth behind statements.
According to data journalist Paul Bradshaw, "scepticism is important in journalism because it moves us from merely repeating what people have said, to establishing the factual basis that puts that information into context.
"Scepticism is also another example of the journalist exercising their imagination: the sceptical journalist must always ask 'But what if this information is not true? — what if?'"
For more tips on how to question what sources say, head to this Online Journalism Blog post.