That really depends on which philosophy you subscribe to.
The TL;DR is that existential and post-modern philosophy say it's varying degrees of relative, while everything anyone said before ~1800 was saying that facts were immutable.
One fact I can glean is that the data itself may be real (e.g., the wavelengths of light that hit your eyeballs) but the perception is a composite illusion of our mind (e.g., the fact that you just saw a kitty).
ooh, yes I see your point. I think both can be true, and a third; we think we (aka scientists) know how something is, but later finds out it works in a different way. The fact never changed, we just learned what it actually is.
example: red pandas used to be categorised with the gigant pandas (that are closer to regular bears) but after we've learned more about the red pandas they are actually closer to raccoons.
I don't know what I'm trying to say. I hope I understood you correctly, English isn't my first language.