To be admissible at trial, evidence must be relevant.
"Relevance links the admissibility to evidence to substantive law and to the common sense patterns of inference."
Even relevant evidence need not be admissible to be discoverable, according to FRCP 26(b)(1).
How do we know what's relevant?
Must be related to a party's claim or defense.
Old Rule: had to have related to the subject matter of the case/action.
Process for Determining Relevance
First, examine the complaint and the answer.
This will tell/give you a sense as to what the parties' claims/defenses are.
Second, examine the case law upon discovery to understand what all is involved in like cases.
Fed. R. Ev. 401: "relevance"
evidence is relevant if it has any tendency to make a fact more or less probably than it would be without the evidence and the fact is of consequence in determining the action.
Does relevant here mean that information sought will necessarily be admissible at trial?
No; the purpose of discovery is to find things that will lead to more information, but the purpose of evidence at trial is to act as settled fact.