I've recently played this card in a Norman Withers deck. Of course, you can't actually upgrade the card due to his deck-building restrictions, but while other customizable cards aren't that impressive or don't really seem to do much at level 0 (looking at you, Summoned Servitor), this does bank card draw at level 0, if you can manage to succeed by 3 consistently (or fail I guess but why fail when you can succeed?)

I was able to trigger the "succeed on a test by 3" criteria pretty much every round. Norman's 5 book paired with the new Grim Memoir allowed me investigate at 7, and our good friend Dr. Milan Christopher brings that to an 8 without commits. I would more often than not commit Enraptured from my Astronomical Atlas to replace the Grim Memoir secrets, which put me up to 9. On normal difficulty, this beats pretty much every chaos token, and more often than not I'd be right at succeeding by 3.

The banked card draw on Empirical Hypothesis was really nice to make the most out of Norman's once-per-round ability, and helped immensely when trying to cycle out Deductions, Enraptureds, and other useful cards from the deck once The Harbinger was gone to regain tempo.

0xp: Empirical Hypothesis is almost similar as Lucky Cigarette Case. Let's assume we always choose the criteria "You succeed at a test by 3 or more," since this criteria is more robust to trigger than the other. Then, Empirical Hypothesis is just non-slot LCC(0). Of course, we need 1 additional succeed and cannot trigger during just played round (since we choose the criteria at the start of the round). However, we can choose the timming of the draw. It's useful if we want to shuffle the thin deck just before resolving the weakness or shuffle empty deck before searching the deck. For easy/standard difficulty, 0xp version is still good and even hard difficulty I think good^a.

0xp is enough good, so we may not upgrade this card. The below part is related to the upgrade and just as reference.

3xp: I suggest the 3xp upgrade as Field Research + Peer Review. It's a note that the criteria is chosen at the start of the round, before the encounter cards are drawn during the mytho phase. In this reason, it's hard to guess which criteria is suitable. I think, Field Research + Peer Review is easy to trigger. With Field Research + Peer Review, Empirical Hypothesis is triggered if we're in the location with 3+ shroud and another investigator is in our location^b.

Another upgrade candidates:

• Alternative Hypothesis(4xp): For multiplayer, we have two great criteria: Field Research, 3+ succeed. One problem is that we check which one is first and choose one.
• Research Grant(2xp): If you have not enough money source, this upgrade gives backup plan. This upgrade converts 2 cards into 3 resources, which is common trade ratio in AHLCG. Considering 2xp upgrade, it's not efficient trade but fair trade (or backup plan).
• One criteria considering your group: If we upgrade all above, Empirical Hypothesis is now 9xp and we have Peer Review. For easlier triggering of Alternative Hypothesis, one additional criteria is good, IMO. For instance, Trial and Error with Mark. Independent Variable is also considerable as second criteria with Alternative Hypothesis.

I do not recommand Irrefutable Proof. Commonly, drawing 3 cards is valuable than discovering 1 clue^a.

a) I has not play expert difficulty. This may not true for expert difficulty.

b) Since the text states "when the chosen criteria is met", this ruling may be wrong. IMO, when is not meaning as triggering timing considering the movement of the unrevealed location.

□□ Peer Review not only easier fill evidences but also allow sharing ability :

• 1 evidence → Draw : Others with you can draw in weird timing, such as before a test to find more commits or Fast play card, so it may translates to better Mythos Phase defense. Someone that can discard for benefit or playing big hand may want to quickly grab a card mid fight where normally they had to take AoO. Generically good to share.
• 2 evidence → □□ Research Grant looked the most interesting to me :
  • No expiration. Other investigator can carry on the discount and play a card later at possibly different location. You just need to meet up briefly to distribute the discount ahead of time.
  • Several offensive event costs 3+ and you hold them waiting to play at the right moment. Banked discount sticks with you ready to be used with the event.
  • Can spend 4 evidences to get -6 discount for the next card. Maybe useful for some high end assets.
  • But the banked discount may discourage players to play a card with no cost / low cost.
• 3 evidence → □□□ Irrefutable Proof : Almost equal to you activating it by yourself, except the clue go to the other player. Maybe someone needs to drop it, protect against treachery that ask to drop clues, to enter a location, or have some kind of ability that triggers on discovering a clue? This looked niche to me.

So, this cards calls running out of cards a "pessmistic outlook", and getting beaten or horrified "trial and error". That's quite a gamemaster's point of view on pedagogy. For 200 characters, I'll add it does seem promising getting it with "alternative hypothesis" for whoever gets two Quick Learner.