Abstract

Personal as well as scientific evidence that leads to the conviction that paranormal phenomena exist is often based on personal experiences. It is important to formulate criteria that constitute personal or scientific evidence. In this article, the author discusses 2 models, a classical and a nonclassical, of how to produce evidence, each leading to different experimental paradigms. The usual classical criteria for scientific evidence are effect oriented. Experimental results of parapsychology seem unable to fulfill these requirements. One gets the impression that an erosion of evidence rather than an accumulation of evidence is taking place. This results in a discrepancy between personal and scientific evidence. A person who reports a paranormal experience gets the impression that the scientific description of it is inadequate. This is called the Hans-in-luck-syndrome. The nonclassical model for scientific evidence is development oriented instead of effect oriented. It takes into account the inherent entanglement of psychophysical systems and the fact that such systems have their own history. In such systems, evidence cannot simply be accumulated because the conditions that produce evidence change during the development of the system.