Okay kiddo, let's imagine that you are playing a game of "telephone" with your friends. In this game, you whisper a message to the person next to you and they pass it along until it gets to the last person. But sometimes, the message gets changed along the way and the last person doesn't hear the original message correctly.
Now, let's say you want to find out if the message the last person heard is true. You need to look at something called the "criterion of contextual credibility." This big phrase means that you have to think about the situation the message was shared in and decide if it makes sense for the message to be true.
For example, let's say you whispered "The sky is green" to the first person and by the time it gets to the last person, they heard "The cow can fly." If you use the criterion of contextual credibility, you would know that it doesn't make sense for a cow to fly, so the message is not true.
Using this criterion helps you figure out if something you hear is true or not, based on what you know about the situation it was said in. It's like a special tool to help you be a really good detective and find out the truth!