Which technique involves repeating the essence of an earlier research study with different participants and in different circumstances?

I believe the answer is: Replication

During a replication, Researchers would repeat the research that conducted in the past, but being done with different situations or different type of subjects. The purpose of such research is to determine if the finding on the previous research would be applicable under different circumstances.

answer; by working independently, the states have a high likelihood of developing innovative solutions that can be employed in other states;

i believe the answer is:   psychological  experiment

in this experiment, wilhelm wundt became the first person that implement scientific method in analyzing the pyschological phenomenon.

due to this result, wilhelm wundt also able to make psychology to be acknowledged as a separate scientific field from biology.