In recent discussions of the roles of experimental evidence in science, there have been two opposing positions. Dr. Franklin, along with others, has argued for an "evidence model" of science in which questions concerning theory choice, confirmation, refutation, etc. are decided on the basis of valid experimental evidence. Others have argued that science is merely a social construction, and that the social and/or cognitive interests of the scientific community play the major role, with experimental evidence playing at most a minor role. Dr. Franklin, under this grant, is investigating further arguments in favor of the "evidence model." He believes that by considering the context of pursuit, the reasons why scientists pursue a particular research program, rather than the context of justification, one might be able to reconcile the two views. This work continues the current trend in history and philosophy of science of considering the actual practice of science. On the basis of this work as well as work by other philosophers and historians, Dr. Franklin hopes to present a more complete philosophy of experiment.