development of Campbell's ideas In the 1990s, Campbell's formulation of the mechanism of "blind-variation-and-selective-retention" (BVSR) was further developed and extended to other domains under the labels of "universal selection theory" or "universal selectionism" by Gary Cziko, Mark Bickhard, and Francis Heylighen. In 2000, a group of 85 social and behavioural scientists and social practitioners from 13 countries met in Philadelphia, USA and founded the Campbell Collaboration. The collaboration aims to address the need for an organisation that produces systematic reviews of research evidence on the effectiveness of social interventions. Many of the people involved in the establishment of the Campbell Collaboration were from Cochrane. Selected works 1959, with Donald W. Fiske, "Convergent and discriminant validation by the multitrait-multimethod matrix, In: Psychological Bulletin 56/1959 No. 2, pp. 81-105. 1963, with Julian C. Stanley, "Experimental and Quasi-Experimental Designs for Research. 1965, "Variation and selective retention in socio-cultural evolution". In: Herbert R. Barringer, George I. Blanksten and Raymond W. Mack (Eds.), Social change in developing areas: A reinterpretation of evolutionary theory, pp. 19–49. Cambridge, Massachusetts: Schenkman. 1969, "Ethnocentrism of disciplines and the fish-scale model of omniscience, In: M. Sherif & C. W. Sherif (Eds.), Interdisciplinary Relationships in the Social Sciences, Boston 1969, pp. 328-348 1970, "Natural selection as an epistemological model". In Raoul Naroll and Ronald Cohen (Eds.), A handbook of method in cultural anthropology, pp. 51–85. New York: National History Press. 1972, "On the genetics of altruism and the counter-hedonic components in human culture". Journal of Social Issues 28 (3), 21-37. 1974, "Downward causation in hierarchically organised biological systems". In Francisco Jose Ayala and Theodosius Dobzhansky (Eds.), Studies in the philosophy of biology: Reduction and related problems, pp. 179–186. London/Basingstoke: Macmillan. 1974, Unjustified variation and retention in scientific discovery. In Francisco Jose Ayala and Theodosius Dobzhansky (Eds.), Studies in the philosophy of biology: Reduction and related problems, pp. 141–161. London/Bastingstoke: Macmillan. 1974, "Evolutionary Epistemology." In The philosophy of Karl R. Popper edited by P. A. Schilpp, 412-463. LaSalle, IL: Open Court. 1975, "On the Conflicts between Biological and Social Evolution and between Psychology and Moral Tradition." American Psychologist 30: 1103-26. 1976, "Assessing the Impact of Planned Social Change," Occasional Paper Series, Paper #8, The Public Affairs Center, Dartmouth College. 1979, "Quasi-Experimentation: Design and Analysis Issues for Field Settings" with Thomas D. Cook. 1987, "Evolutionary epistemology." In: Evolutionary epistemology, rationality, and the sociology of knowledge, pp. 47–89. 1990, "Epistemological roles for selection theory,"