Observation is key. In the pacific islands, during WW2, troops would give food and stuff to natives as a sort of bribe for building air bases on their land. After the war ended, the troops all moved out. But the natives sat in radio towers with headphones that they constructed out of bamboo and whatnot. You see, they thought that by mimicking base operations, they could get stuff again.
Another example would be the story of the scientist testing how far a frog can jump. He nudges the frog, and it jumps 4 feet. Amputates one leg, nudges again, 3 feet. This continues until the frog has no legs, and does not jump when nudged. The scientist concludes that a frog with no legs is dead. I know of an alternate version of this, where the conclusion is that crickets hear through there legs.
Basically, just eliminate the variables and you're more likely to get it right.
_________________
When I allow it to be
There's no control over me
I have my fears
But they do not have me