A more thorough explanation:

A quantitative rule is an evidentiary rule that requires additional evidence to be presented before a case can be closed. This rule exists because certain types of evidence are known to be weak or unreliable on their own.

For example, hearsay evidence is often considered unreliable because it is based on secondhand information. Therefore, a quantitative rule may require that hearsay evidence be accompanied by additional evidence before it can be used to make a decision in a case.

Another example of a quantitative rule is the requirement for multiple witnesses to corroborate a piece of evidence. This is because a single witness may be mistaken or biased, but multiple witnesses providing the same information increases the likelihood that the evidence is accurate.

Overall, the purpose of a quantitative rule is to ensure that decisions are based on strong and reliable evidence, rather than on evidence that may be weak or misleading on its own.