Preponderance of evidence is the most common measure used to decide whether something is true or not. It means that it is more likely than not (more than 50% chance) that something is true, based on the evidence. For example, if a judge is hearing a case about whether someone stole a car, the judge may look at all of the evidence and decide that it is more likely than not that the person did steal the car. That is the preponderance of evidence.