Although not known by the public, parapsychology has been plagued by criticism from mainstream science. Parapsychologists have always found this bias unfair, as the methods used in parapsychology are the exact same as those used in conventional science (and in many cases, more strict). Despite this, and a growing body of research that validates psychic ability, mainstream science denies the findings, and believes that parapsychology should be set to a different set of scientific standards.
Williams work reviews the debate over the validity of the evidence of psi. He debates that the research that looks at large numbers of psi studies (called meta-analysis), has sufficiently demonstrated that psi exists by professional scientific standards. Critics claim that different methods should be used to prove psi that uses different probabilities (a Bayesian analysis).
Williams provides a modified analysis method that he believes will satisfy critics. However, his core theme is that the evidence for psi is sufficient, and there are some dangers of abuse with other research methods. Ultimately, Williams claims that it is not the method, but scientists beliefs that are keeping psi research from reaching popular acceptance.
Williams, G. (2015). Are different standards warranted to evaluate psi? Journal of Parapsychology, 79, 186-202.