A more thorough explanation:

Definition: The outcome-determinative test is a method used in civil procedure to determine whether an issue is substantive or procedural for the purpose of the Erie doctrine. This test examines the potential effect of the issue on the outcome of the litigation.

Example: Let's say a plaintiff files a lawsuit in a state court, and the defendant argues that the case should be dismissed because the court lacks jurisdiction. The outcome-determinative test would be used to determine whether the issue of jurisdiction is substantive or procedural. If the court determines that the issue is substantive, it would apply the law of the state where the lawsuit was filed. If the issue is procedural, the court would apply federal law.

Explanation: This example illustrates how the outcome-determinative test is used to determine whether an issue is substantive or procedural. If the issue of jurisdiction is substantive, it could potentially affect the outcome of the case, and therefore the court would apply state law. If the issue is procedural, it would not affect the outcome of the case, and the court would apply federal law.