In this sense, the human scale is the central scale, because ultimately the human mind must have the opportunity to weigh observation and put together its own picture of the world. One of the ways we all do that is through trial and error. Trial and error is a tool at many scales.
Wrong answers lead to the right answers.
Trial and error offers an extraordinarily direct feedback loop for the investigator. Few people were more avid practitioners of it than Thomas Edison, the inventor of the light bulb. He tried many, many materials to make that light bulb work and was prepared to try many more. One of the limitations of trial and error as an approach can also be seen through Edison. When radioactivity was first discovered, he, like many others, took to exploring by trying everything, holding the uranium, playing with it, etc.