The status of something as evidence is partly down to a judgement about relevance. If some random person in 1970 jokingly were to have said "Yeah, I killed JFK

The status of something as evidence is partly down to a judgement about relevance. If some random person in 1970 jokingly were to have said "Yeah, I killed JFK." That wouldn't have been considered "evidence" of that person's culpability in JFK's death. But if there were other evidence that established the plausibility of that person having possibly killed JFK (worked at the Book Depository, hated JFK, owned a rifle, expert markmsman, etc...) then the statement becomes a kind of evidence-- a confession. So the status of something as "evidence" and not merely data can change based on the context. Here's another example. There was water all over the floor of my kitchen. Initially, we suspected that I may have spilled some water while filling a humidifier. There was evidence for that in the form of my own memory that I had spilled some, a few hours earlier, and there were water streaks down the side of the humidifier. This seemed to be supprting evidence. But then my wife remembered that she had filled a pan to check for leaks in it and then forgot all about it. That pan was now empty. In light of that evidence, which was very compelling (we even verified that there was indeed a leak in that pan) the earlier "evidence" STOPPED being evidence at all.