This paper presents a brief review of the debate between parapsychologists and skeptics regarding the issue of replication in experimental tests of extrasensory perception (ESP) using a sensory reduction technique known as ganzfeld. The review is followed by a basic assessment of 59 ganzfeld ESP studies reported in the period following the publication of a stringent set of methodological guidelines and recommendations by R. Hyman and C. Honorton in 1986. The assessment indicates that these 59 studies have a combined hit (...) rate of approximately 30%, which is significantly above the chance expected hit rate of 25%. A comparison of the hit rates across four ganzfeld meta-analyses, as well as across fifteen laboratories, seems to further indicate replication of the ganzfeld ESP effect by a broad group of independent researchers. Keywords: extrasensory perception (ESP)—ganzfeld—meta-analysis—psi—parapsychology. (shrink)

Throughout the debate on psi, skeptics have almost universally insisted on different standards for evaluating the evidence, claiming that psi represents a radical departure from our current scientific understanding. Thus, there is considerable ambiguity about what standard of evaluation psi must meet. Little attention has been paid to the possible harm to the integrity of scientific investigation from this resulting inconsistency in testing standards. Some have proposed using a Bayesian framework as an improvement on this dilemma in order to more (...) explicitly model beliefs, assumptions, and background scientific knowledge, especially when evaluating a controversial hypothesis. Recently, Kuhn’s notion of paradigms, which constrains scientific research within bound- aries believed to be most productive, has been incorporated into a Bayesian framework. Within this framework, I explore a likely paradigm or meta-theory used by skeptics that typically constrains research and makes it difficult for psi evidence to be accepted. It appears that such a paradigm would in many respects have difficulty accounting for consciousness, which is fundamental to an understanding of psi. I discuss why psi data are likely to play a key role in making progress in solving the problem of consciousness. Thus, applying different standards of evaluation to psi data is likely counterproductive. (shrink)

Speculations about the role of consciousness in physical systems are frequently observed in the literature concerned with the interpretation of quantum mechanics. While only three experimental investigations can be found on this topic in physics journals, more than 800 relevant experiments have been reported in the literature of parapsychology. A well-defined body of empirical evidence from this domain was reviewed using meta-analytic techniques to assess methodological quality and overall effect size. Results showed effects conforming to chance expectation in control conditions (...) and unequivocal non-chance effects in experimental conditions. This quantitative literature review agrees with the findings of two earlier reviews, suggesting the existence of some form of consciousness-related anomaly in random physical systems. (shrink)

Over the past hundred years, a number of scientific investigators claim to have adduced experimental evidence for phenomena information” seems to behave like a weak signal that has to compete for the information-processing resources of the organism, a reduction of ongoing sensorimotor activity may facilitate ESP detection. Such a meaningful convergence of results suggests that psi phenomena may represent a unitary, coherent process whose nature and compatibility with current physical theory have yet to be determined. The theoretical implications and potential (...) practical applications of psi could be significant, irrespective of the small magnitude of psi effects in laboratory settings. (shrink)

Jednou z hlavních námitek proti parapsychologii je, že její experimenty nejsou replikovatelné. Z diskuse mezi obhájci a kritiky tohoto oboru však vysvítá, že obě strany chápou požadavek replikace odlišným způsobem. Na základě sporu o parapsychologii lze rozlišit několik typů replikace – statistickou replikaci, krátkodobě a dlouhodobě spolehlivou replikaci, dva typy nezávislé replikace, retrospektivní a prospektivní replikaci. Bez explicitního rozlišování těchto různých kritérií nelze o problému parapsychologie konstruktivně diskutovat.

I address some specific problems in the two target articles offered here (Rao and Palmer/Alcock: Parapsychology review and critique), which are indicative of more general problems that plague the larger debate. Because such problems are rather typical of scientific conflict, I address general problems of assessment in a second section. In a final section. I make some comments about the future of this debate.