Theory of Physical Undecidability
The popular holo-course "Invisible Science 101" says: "The Theory of Physical Undecidability is a set of mathematical models and axioms which observe how some things can never be observed."
Here we will discuss it from the lens of xenosociology, specifically in terms of why anthropologists flock to the Bottlenose Nebula's primitive alien societies.
At some point, scientists will find things they cannot properly test or verify.
While some are hopeful that a new instrument or experiment will be invented, there are barriers no species has ever been recorded surpassing. We cannot create a new multiverse, so our models on multiverse formation remain conjecture. We cannot peer through an event horizon despite faster than light travel - why? There are many possibilities, but which one is right?
We can talk about how civilizations form and behave, but we cannot create variants to test our conjectures.
Impact on Xenosociology
While the overall behavior of civilizations is fairly well understood at this point, there are large gaps at the "top" and "bottom". As the example goes: you can understand how a plastic ball bounces, but that doesn't tell you how the atoms in the ball behave, or what would happen if a ball was traveling at light speed. Anyone studying culture comes to this same conclusion.
Unfortunately, civilization is not a plastic ball.
Some scientists have attempted to alter civilizations to test their theories, but there's no base result to compare to. If you split a society into A/B groups, that has radically more impact than whatever you were trying to test!
Similarly, some scientists have attempted to create civilizations, such as the Test Tube Territories scattered on the coreward edge of the Bottlenose Nebula. Again, the effect of being carefully controlled has more impact than anything else you could try to test. You can't even effectively test how civilizations respond to being controlled, since even 'uncontrolled' subjects were created under controlled conditions.
Most modern xenosociologists attempt to master "stamp collecting": if we gather enough samples, we'll find civilizations with enough similarities that their differences will reveal patterns more clearly!
Because it's impossible to clone our universe and do A/B testing, the fundamental laws governing the development of civilization are hard to discern. There are many, contradictory models that work reasonably well, but when a model fails to predict something, is the model wrong? Or is there just some factor not taken into account?
This is the challenge facing all those in our field.
So we collect as many samples as possible. By carefully comparing samples, we can find similarities and differences that were previously foggy and undiscovered.
Therefore, it is critical that you follow the standards set forth by the Interstellar Sociologist's Foundation, and gather data specifically on the factors most in need of samples. Moreover, it is critical you allow these societies to develop undisturbed: we must take repeated samples from clean data sources.