Evaluate the evidence for the belief or knowledge claim. Ask if the evidence supports the claim. Keep in mind that evidence that is relevant depends on the type of belief or knowledge at stake. Scientific method is concerned with empirical evidence that can be measured, weighed and observed. However, making an aesthetic or ethical claim usually involves nonempirical types of evidence. Finally, a legal proceeding also depends on evidence that may be a combination of logical reasoning and empirical evidence. Finding a defendant guilty in a court of law depends on the prosecutor presenting evidence that undeniably proves the defendant's guilt.
Examine the argument for hidden weaknesses and flaws. Even if the evidence for a claim seems convincing at first, critically evaluating and analyzing the claim may expose weaknesses and flaws. The example of a jury illustrates this point as well. A jury has two primary tasks: 1) to critically listen to the evidence for both sides; and 2) to critically weigh and judge the evidence. Another example is a scientist, who makes a claim based on scientific research. The scientific community scrutinizes the claim analytically to ensure that the claim and arguments are sound. Logical flaws are another example. A typical logical flaw is an "ad hominen" fallacy that claims to discredit an argument when it actually only attacks the person making the claim and leaves the argument untouched.
View the topic or issue from a variety of angles and perspectives. This is an example of the Socratic method. Socrates engaged in dialogue with his interlocutors about a specific topic, such as the meaning of justice and love. The point of the dialogue is to present different definitions or viewpoints on the issue. A definition is presented, discussed and debated. The goal of the Socratic dialogue is to arrive at the true definition. This is done by diagnosing the inadequacies of definitions until the true definition reveals itself.
Continue analyzing an issue or topic until you have a good grasp and can understand the details. Plato distinguished between knowledge and opinion. He also made an additional distinction between right opinion and wrong opinion. Right opinion happens to be right but without really understanding why. Knowledge, on the other hand, is able to provide a rational explanation for a belief or knowledge claim. In other words, it understands the evidence that supports the claim.