Answer:
controlled experiments
Step-by-step explanation:
Science is based on systematic observation records. Scientific theories are an attempt to explain those observations based on the current understanding of the laws of the Universe. Theories are considered to be supported by evidence when that evidence is provided by "controlled experiments".
An experiment is considered a "controlled experiment" when it is repeatable, and includes protocols to eliminate experimenter bias and any other possible confounding causes of the result being tested.
_____
Comment on "controlled experiments"
Quantum theory tells us that "spooky action at a distance" is an effect built into the design of the Universe. That is, there's no such thing as eliminating experimenter bias. Every experiment is conducted in the context of the energy fields of the experimenters (and others, known or unknown), so cannot ever be said to be isolated from outside influence.
We note, too, that "controlled" is with respect to the current understanding of the laws of the Universe. As we gain understanding, we realized experiments previously thought to be well-designed, in fact, were subject to influences that were unaccounted for.