Donald Campbell

Donald Campbell was an influential American psychologist known for his work on social science research methods and the philosophy of science. He is best recognized for developing the concept of the "Campbell's law," which highlights how the use of measures to evaluate social programs can lead to unintended consequences. Campbell emphasized the importance of rigorous research design, advocating for methods that ensure validity and reliability of results. He also contributed to concepts like "validity" in testing, and his ideas have significantly shaped the fields of psychology, education, and social research.