I've been thinking about this for a while, and I'm not really sure how to address it. I read a GM tip once that stated that a low roll shouldn't mean the player learns nothing. I've taken to coming up with bad/sort of false information when my players roll poorly on perception/insight/etc.
For instance: If there's a cavern with a door in one wall, covered completely by some ivy, and a player rolls a four on their investigation check, I might tell them something like "You're very sure there's nothing on that wall." Or, if there are children playing on an otherwise-deserted street, and a player makes an investigation check to see if they can see anything else and rolls a crit failure, I might tell them they think they see movement out of the corner of their eye behind some buildings - that kind of thing.
I'm wondering what are the ramifications/consequences of this. I want my players to trust me, but I also think it's important that low rolls mean something. Is this style of GMing wrong? Should a failed check just mean that I tell the player they don't know/don't see anything? Or should I keep this up? I don't want to deceive my players, but I feel like it keeps the suspension of disbelief better if a failure doesn't just mean "no, you see nothing, next dice roll."