This essential work in social measurement arguments as to why qualitative approaches belong with quantitative ones; a debate with deconstructionists and social constructionists on measurement validity, and an expansion and further explanation of the multitrait-multimethod matrix.
American social scientist. He is noted for his work in methodology. He coined the term "evolutionary epistemology" and developed a selectionist theory of human creativity. A Review of General Psychology survey, published in 2002, ranked Campbell as the 33rd most cited psychologist of the 20th century.