Parapsychology (from the Greek: παρά ''para'', "alongside" + ''psychology'') is the study of ostensibly paranormal psychological phenomena. Phenomena studied include extra-sensory perception, psychokinesis, and survival of consciousness after death; parapsychologists call these phenomena ''psi'', a neutral term non-suggestive of what causes the phenomena or experiences.Thouless, R. H. (1942). "Experiments on paranormal guessing". ''British Journal of Psychology'', ''33'', 15–27.

Parapsychological research involves a variety of qualitative and quantitative methodologies, and takes place at a small number of universities and privately funded laboratories, notably in the United States and the United Kingdom. The research has been published in mainstream journals including ''Psychological Bulletin'', ''Foundations of Physics'', and the ''British Journal of Psychology'', as well as specialist publications such as the ''Journal of Parapsychology''. Experiments conducted by parapsychologists have included the use of random number generators to test for evidence of psychokinesis, sensory-deprivation Ganzfeld experiments to test for extra-sensory perception, and research trials conducted under contract to the United States government to investigate the possibility of remote viewing. Parapsychologists have generated a number of meta-analytical studies based on this research, which combine the data from previous experiments into one large data set. These statistical analyses have attracted much attention and debate.

Parapsychology is a fringe science because it involves research that does not fit within standard theoretical models accepted by mainstream science. Scientists such as psychologists Ray Hyman and James Alcock, among others, are critical of both the methodology used and the results obtained by parapsychology. Skeptical researchers suggest that methodological flaws provide the best explanation for apparent experimental successes, rather than the anomalistic explanations offered by many parapsychologists. Critical analysts argue that parapsychology crosses the line into pseudoscience. To date, no evidence has been accepted by the mainstream scientific community as irrefutably supporting the existence of paranormal phenomena.

Early psychical research

The Society for Psychical Research (SPR) was founded in London in 1882. The formation of the SPR was the first systematic effort to organize scientists and scholars for a critical and sustained investigation of paranormal phenomena. The early membership of the SPR included philosophers, scholars, scientists, educators and politicians, such as Henry Sidgwick, Arthur Balfour, William Crookes, and Charles Richet.

The SPR classified its subjects of study into several areas: telepathy, hypnotism, Reichenbach's phenomena, apparitions, haunts, and the physical aspects of spiritualism such as table-tilting and the appearance of matter from unknown sources, otherwise known as materialization. One of the first collaborative efforts of the SPR was its ''Census of Hallucinations'', which researched apparitional experiences and hallucinations in the sane. The census was the Society's first attempt at a statistical evaluation of paranormal phenomena, and the resulting publication in 1886, ''Phantasms of the Living'' is still widely referenced in parapsychological literature today. The SPR became the model for similar societies in other European countries and the United States during the late 19th century. Largely due to the support of psychologist William James, the American Society for Psychical Research (ASPR) opened its doors in New York City in 1885.

Today, the SPR and ASPR continue the investigation of psi phenomena. The SPR's purpose is stated in every issue of its ''Journal'' - being "to examine without prejudice or prepossession and in a scientific spirit those faculties of man, real or supposed, which appear to be inexplicable on any generally recognized hypothesis."

Rhine era

In 1911, Stanford University became the first academic institution in the United States to study extra-sensory perception (ESP) and psychokinesis (PK) in a laboratory setting. The effort was headed by psychologist John Edgar Coover. In 1930, Duke University became the second major U.S. academic institution to engage in the critical study of ESP and psychokinesis in the laboratory. Under the guidance of psychologist William McDougall, and with the help of others in the department—including psychologists Karl Zener, Joseph B. Rhine, and Louisa E. Rhine—laboratory ESP experiments using volunteer subjects from the undergraduate student body began. As opposed to the approaches of psychical research, which generally sought qualitative evidence for paranormal phenomena, the experiments at Duke University proffered a quantitative, statistical approach using cards and dice. As a consequence of the ESP experiments at Duke, standard laboratory procedures for the testing of ESP developed and came to be adopted by interested researchers throughout the world.

The publication of J.B. Rhine's book, ''New Frontiers of the Mind'' (1937) brought the laboratory's findings to the general public. In his book, Rhine popularized the word "parapsychology," which psychologist Max Dessoir had coined over 40 years earlier, to describe the research conducted at Duke. Rhine also founded an autonomous Parapsychology Laboratory within Duke and started the ''Journal of Parapsychology'', which he co-edited with McDougall.

The parapsychology experiments at Duke evoked much criticism from academic psychologists who challenged the concepts and evidence of ESP. Rhine and his colleagues attempted to address these criticisms through new experiments, articles, and books, and summarized the state of the criticism along with their responses in the book ''Extra-Sensory Perception After Sixty Years''.

The administration of Duke grew less sympathetic to parapsychology, and after Rhine's retirement in 1965 parapsychological links with the university were broken. Rhine later established the Foundation for Research on the Nature of Man (FRNM) and the Institute for Parapsychology as a successor to the Duke laboratory. In 1995, the centenary of Rhine's birth, the FRNM was renamed the Rhine Research Center. Today, the Rhine Research Center is a parapsychology research unit, stating that it "aims to improve the human condition by creating a scientific understanding of those abilities and sensitivities that appear to transcend the ordinary limits of space and time."

Establishment of the Parapsychological Association

The Parapsychological Association (PA) was created in Durham, North Carolina, on June 19, 1957. Its formation was proposed by J. B. Rhine at a workshop on parapsychology which was held at the Parapsychology Laboratory of Duke University. Rhine proposed that the group form itself into the nucleus of an international professional society in parapsychology. The aim of the organization, as stated in its Constitution, became "to advance parapsychology as a science, to disseminate knowledge of the field, and to integrate the findings with those of other branches of science".

Under the direction of anthropologist Margaret Mead, the Parapsychological Association took a large step in advancing the field of parapsychology in 1969 when it became affiliated with the American Association for the Advancement of Science (AAAS), the largest general scientific society in the world. In 1979, physicist John A. Wheeler argued that parapsychology is pseudoscientific, and that the affiliation of the PA to the AAAS needed to be reconsidered.{{cite book | author = John Archibald Wheeler | title = Geons, Black Holes, and Quantum Foam: A Life in Physics | publisher = W. W. Norton | year = 1998 | id = ISBN 0-39304-642-7 | url = http://books.google.com/books?id=Yk5cth-oZmQC&pg=PA343&lpg=PA343&dq=aaas+meeting+parapsychology&source=web&ots=6QhZmeLkBy&sig=ZuSfhM0YvTScEm-rvZ1GDVlVpyU
}}
His challenge to parapsychology's AAAS affiliation was unsuccessful. Today, the PA consists of about three hundred full, associate, and affiliated members worldwide and maintains its affiliation with the AAAS.{{cite book |last=Irwin |first=Harvey J. |authorlink = |title=An Introduction to Parapsychology, Fourth Edition |publisher=McFarland & Company |date=2007 |pages= |url=http://books.google.com/books?id=jB88qA7C9oYC&dq=An+Introduction+to+Parapsychology.&pg=PP1&ots=L53QIyz2qx&sig=-2bQfPeTt1QDFDJN_RzNSgQ4ZCs&prev=http://www.google.com/search%3Fhl%3Den%26client%3Dfirefox-a%26channel%3Ds%26rls%3Dorg.mozilla:en-US:official%26hs%3D0AF%26sa%3DX%26oi%3Dspell%26resnum%3D0%26ct%3Dresult%26cd%3D1%26q%3DAn%2BIntroduction%2Bto%2BParapsychology.%26spell%3D1&sa=X&oi=print&ct=title
|isbn=0786418338 |accessdate=2007-07-31}} The annual AAAS convention provides a forum where parapsychologists can present their research to scientists from other fields and advance parapsychology in the context of the AAAS's lobbying on national science policy.

Decade of increased research (1970s)

The affiliation of the Parapsychological Association (PA) with the American Association for the Advancement of Science, along with a general openness to psychic and occult phenomena in the 1970s, led to a decade of increased parapsychological research. During this period, other notable organizations were also formed, including the Academy of Parapsychology and Medicine (1970), the Institute of Parascience (1971), the Academy of Religion and Psychical Research, the Institute of Noetic Sciences (1973), the International Kirlian Research Association (1975), and the Princeton Engineering Anomalies Research Laboratory (1979). Parapsychological work was also conducted at the Stanford Research Institute during this time.

The scope of parapsychology expanded during these years. Psychiatrist Ian Stevenson conducted much of his controversial research into reincarnation during the 1970s. Psychologist Thelma Moss devoted time to the study of Kirlian photography at UCLA's parapsychology laboratory. The influx of spiritual teachers from Asia, and their claims of abilities produced by meditation, led to research on altered states of consciousness. Physicist Russell Targ introduced the term remote viewing in 1974.

During this period, academics outside parapsychology also appeared to have a general optimism towards this research. In 1979, a survey of more than 1,100 college professors in the United States found that only 2% of psychologists expressed the belief that extra-sensory perception was an impossibility. A far greater number, 34%, indicated that they believed ESP was either an established fact or a likely possibility. The percentage was even higher in other areas of study: 55% of natural scientists, 66% of social scientists (excluding psychologists), and 77% of academics in the arts, humanities, and education believed that ESP research was worthwhile.

The surge in paranormal research continued throughout the 1970s and into the 1980s. By the end of the 1980s, the Parapsychological Association reported members working in more than 30 countries. Additionally, research not affiliated with the PA was being carried out in Eastern Europe and the former Soviet Union.

Parapsychology today

Contemporary parapsychological research has waned considerably. Early research was considered inconclusive, and parapsychologists were faced with strong opposition from their academic colleagues. Some effects thought to be paranormal, for example, the effects of Kirlian photography, disappeared under more stringent controls, leaving those avenues of research at dead-ends. Many university laboratories in the United States have closed, citing a lack of acceptance by mainstream science as the reason, leaving the bulk of parapsychology confined to private institutions funded by private sources. After 28 years of research, Princeton Engineering Anomalies Research Laboratory (PEAR) retired their laboratory in 2007.

Two universities in the United States still have academic parapsychology laboratories: the Division of Perceptual Studies, a unit at the University of Virginia's Department of Psychiatric Medicine, studies the possibility of survival of consciousness after bodily death; the University of Arizona's Veritas Laboratory conducts laboratory investigations of mediums. Several private institutions, including the Institute of Noetic Sciences and others, conduct and promote parapsychological research. Britain leads parapsychological study in Europe, with privately funded laboratories at the universities of Edinburgh, Northampton, and Liverpool Hope, among others.

Parapsychological research has also been augmented by other sub-disciplines of psychology. These related fields include transpersonal psychology, which studies transcendent or spiritual aspects of the human mind, and anomalistic psychology, which examines paranormal beliefs and subjective anomalous experiences in traditional psychological terms.{{cite book |last=Cardena |first=Etzel |authorlink= |title=Varieties of Anomalous Experience: Examining the Scientific Evidence
|publisher=American Psychological Association (APA) |date=2004 |pages= |isbn=1557986258}}

Scope

Parapsychologists study a number of ostensible paranormal phenomena, including but not limited to:

Telepathy: Transfer of information on thoughts or feelings between individuals by means other than the five classical senses.

Precognition: Perception of information about future places or events before they occur.

Clairvoyance: Obtaining information about places or events at remote locations, by means unknown to current science.

Psychokinesis: The ability of the mind to influence matter, time, space, or energy by means unknown to current science.

Reincarnation: The rebirth of a soul or other non-physical aspect of human consciousness in a new physical body after death.

Hauntings: Phenomena often attributed to ghosts and encountered in places a deceased individual is thought to have frequented, or in association with the person's former belongings.

The definitions for the terms above may not reflect their mainstream usage, nor the opinions of all parapsychologists and their critics. Many critics, for example, feel that parapsychologists are engaged in the study of phenomena that disappear under stringent experimental conditions and are thus normal processes.

According to the Parapsychological Association, parapsychologists do not study all paranormal phenomena, nor are they concerned with astrology, UFOs, Bigfoot, paganism, vampires, alchemy, or witchcraft.

Ganzfeld

The ganzfeld (German for "whole field") is a technique used to test individuals for telepathy. The technique was developed to quickly quiet mental "noise" by providing a mild, unpatterned sensory field to mask the visual and auditory environment. Isolating the visual sense is usually achieved by creating a soft red glow which is diffused through half ping-pong balls attached to the recipient's eyes. The auditory sense is usually blocked by playing white noise, static, or similar sounds to the recipient. The subject is also seated in a reclined, comfortable position to minimize the sense of touch.

In the typical ganzfeld experiment, a "sender" and "receiver" are isolated. The receiver is put into the ganzfeld state, and the sender is shown a video clip or still picture and asked to mentally send that image to the receiver. The receiver, while in the ganzfeld, is asked to continuously speak aloud all mental processes, including images, thoughts, and feelings. At the end of the sending period, typically about 20 to 40 minutes in length, the receiver is taken out of the ganzfeld and shown four images or videos, one of which is the true target and three are non-target decoys. The receiver attempts to select the true target, using perceptions experienced during the ganzfeld state as clues to what the mentally "sent" image might have been.

According to parapsychologists such as Dean Radin, Charles Honorton, and Daryl Bem, the results of ganzfeld experiments—collectively gathered from over 3,000 individual sessions conducted by about two dozen investigators world-wide—indicate that, on average, the target image is selected by the receiver more often than would be expected by chance alone. Because these meta analyses of ganzfeld results are said to be statistically significant, they have sparked debates within mainstream academic psychology journals over how to properly interpret the data.

Remote viewing

Remote viewing experiments test the ability to gather information on a remote target consisting of an object, place, or person that is hidden from the physical perception of the viewer and typically separated from the viewer at some distance. In one type of remote viewing experiment, a pool of several hundred photographs are created. One of these is randomly selected by a third party to be the target. It is then set aside in a remote location. The remote viewer attempts to sketch or otherwise describe that remote target photo. This procedure is repeated for a number of different targets. Many ways of analytically evaluating the results of this sort of experiment have been developed. One common method is to take the group of seven target photos and responses, randomly shuffle the targets and responses, and then ask independent judges to rank or match the correct targets with the participant's actual responses. This method assumes that if there were an anomalous transfer of information, the responses should correspond more closely to the correct targets than to the mismatched targets.

Several hundred such trials have been conducted by investigators over the past 25 years, including by the Princeton Engineering Anomalies Research Laboratory (PEAR) and by scientists at SRI International and Science Applications International Corp., under contract by the U.S. government. The cumulative data was interpreted by Professor of Aerospace Science Robert G. Jahn and psychologist Brenda Dunne at PEAR as indicating that information about remote photos, actual scenes, and events can be perceived beyond chance expectation.

Psychokinesis on random number generators

The advent of powerful and inexpensive electronic and computer technologies has allowed the development of fully automated experiments studying possible interactions between mind and matter. In the most common experiment of this type, a random number generator (RNG), based on electronic or radioactive noise, produces a data stream that is recorded and analyzed by computer software. A subject attempts to mentally alter the distribution of the random numbers, usually in an experimental design that is functionally equivalent to getting more "heads" than "tails" while flipping a coin. In the RNG experiment, design flexibility can be combined with rigorous controls, while collecting a large amount of data in very short period of time. This technique has been used both to test individuals for psychokinesis and to test the possible influence on RNGs of large groups of people.

Major meta-analyses of the RNG database have been published every few years since appearing in the journal ''Foundations of Physics'' in 1986. PEAR founder Robert G. Jahn and his colleague Brenda Dunne say that the effect size in all cases was found to be very small, but consistent across time and experimental designs, resulting in an overall statistical significance. The most recent meta-analysis was published in ''Psychological Bulletin'', along with several critical commentaries. The meta-analysis was composed of 380 studies, which some researchers say has produced an overall effect size that was very small but statistically significant.

Direct mental interactions with living systems

Formerly called bio-PK, "direct mental interactions with living systems" (DMILS) studies the effects of one person's intentions on a distant person's psychophysiological state. One type of DMILS experiment looks at the commonly reported "feeling of being stared at." The "starer" and the "staree" are isolated in different locations, and the starer is periodically asked to simply gaze at the staree via closed circuit video links. Meanwhile, the staree's nervous system activity is automatically and continuously monitored.

Parapsychologists have interpreted the cumulative data on this and similar DMILS experiments to suggest that one person's attention directed towards a remote, isolated person can significantly activate or calm that person's nervous system. In a meta-analysis of these experiments published in the ''British Journal of Psychology'' in 2004, researchers found that there was a small but significant overall DMILS effect. However, the study also found that when a small number of the highest-quality studies from one laboratory were analyzed, the effect size was not significant. The authors concluded that although the existence of some anomaly related to distant intentions cannot be ruled out, there was also a shortage of independent replications and theoretical concepts.

Near death experiences

A near-death experience (NDE) is an experience reported by a person who nearly died, or who experienced clinical death and then revived. NDEs include one or more of the following experiences: a sense of being dead; an out-of-body experience; a sensation of floating above one's body and seeing the surrounding area; a sense of overwhelming love and peace; a sensation of moving upwards through a tunnel or narrow passageway; meeting deceased relatives or spiritual figures; encountering a being of light, or a light; experiencing a life review; reaching a border or boundary; and a feeling of being returned to the body, often accompanied by reluctance.

Interest in the NDE was originally spurred by the research of psychiatrists Elisabeth Kübler-Ross, George Ritchie, and Raymond Moody Jr. In 1998, Moody was appointed chair in "consciousness studies" at the University of Nevada, Las Vegas. The International Association for Near-death Studies (IANDS) was founded in 1978 to meet the needs of early researchers and experiencers within this field of research. Later researchers, such as neurologist Bruce Greyson, psychologist Kenneth Ring, and cardiologist Michael Sabom, introduced the study of near-death experiences to the academic setting.

Anomalous psychology

A number of studies conducted in the American, European, and Australasian continents have found that a majority of people surveyed report having had experiences that could be interpreted as telepathy, precognition, and similar phenomena. Variables that have been associated with reports of psi-phenomena include belief in the reality of psi; the tendency to have hypnotic, dissociative, and other alterations of consciousness; and, less reliably so, neuroticism, extraversion, and openness to experience. Although psi-related experiences can occur in the context of such psychopathologies as schizotypal personality, dissociative, and other disorders, most individuals who endorse a belief in psi are well-adjusted, lack serious pathology, and are not intellectually deficient or lacking critical abilities.

Criticism

Scientists who are critical of parapsychology begin with the assertion that extraordinary claims demand extraordinary evidence. Proponents of hypotheses that contradict centuries of scientific research must provide extraordinary evidence if their hypotheses are to be taken seriously.{{cite web |last=Gracely, Ph.D. |first=Ed J. |authorlink= |title=Why Extraordinary Claims Demand Extraordinary Proof |work=PhACT |date=1998 |url=http://www.quackwatch.org/01QuackeryRelatedTopics/extraproof.html
|accessdate=2007-07-31}} Many analysts of parapsychology hold that the entire body of evidence to date is of poor quality and not adequately controlled. In their view, the entire field of parapsychology has produced no conclusive results whatsoever. They cite instances of fraud, flawed studies, a psychological need for mysticism, and cognitive bias as ways to explain parapsychological results. Skeptics have also contended that people's desire to believe in paranormal phenomena is often stronger than the evidence that it does not exist.

The reality of parapsychological phenomena and the scientific validity of parapsychological research is a matter of continued dispute. The methods of parapsychologists are regarded by some detractors as a pseudoscience.{{cite web |last=Beyerstein |first=Barry L. |authorlink= |title=Distinguishing Science from Pseudoscience |work=Simon Fraser University |date=1995 |url=http://www.sfu.ca/~beyerste/research/articles/02SciencevsPseudoscience.pdf
|format=PDF |accessdate=2007-07-31}} Some of the more specific criticisms state that parapsychology does not have a clearly defined subject matter, an easily repeatable experiment that can demonstrate a psi effect on demand, nor an underlying theory to explain the paranormal transfer of information. James E. Alcock, Professor of Psychology at York University, said that few of parapsychology's experimental results have prompted interdisciplinary research with more mainstream sciences such as physics or biology. Alcock states that parapsychology remains isolated science to such an extent that its very legitimacy is questionable, and as a whole is not justified in being labeled "scientific".

Fraud

There have been instances of fraud in the history of parapsychology research. The Soal-Goldney experiments of 1941–43 (suggesting precognitive ability in subjects) were long regarded as some of the best in the field because they relied upon independent checking and witnesses to prevent fraud. However, many years later, suspicions of fraud were confirmed when statistical evidence, uncovered and published by other parapsychologists in the field, indicated that Dr. Soal had cheated by altering the raw data.

Walter J. Levy, director of the Institute for Parapsychology, reported on a series of successful ESP experiments involving computer-controlled manipulation of non-human subjects, including eggs and rats. His experiments showed very high positive results. Because the subjects were non-human, and because the experimental environment was mostly automated, his successful experiments avoided criticism concerning experimenter effects, and removed the question of the subject's belief as an influence on the outcome. However, Levy's fellow researchers became suspicious about his methods. They found that Levy interfered with data-recording equipment, manually creating fraudulent strings of positive results. Rhine fired Levy and reported the fraud in a number of articles.

Many spiritualist mediums used fraud, and some were exposed by early psychical researchers such as Richard Hodgson and Harry Price. In the 1920s, magician and escapologist Harry Houdini said that researchers and observers could not create experimental procedures which absolutely preclude fraud. In 1979, magician and debunker James Randi perpetrated a hoax, now referred to as Project Alpha. Randi trained two young magicians and sent them under cover to Washington University's McDonnell Laboratory with the specific aim of exposing poor experimental methods and the credulity thought to be common in parapsychology. Although no formal statements or publications from the McDonnell laboratory supported the likelihood that the effects demonstrated by the two magicians were genuine, both of Randi's trainees reportedly deceived experimenters over a period of four years with demonstrations of supposedly telekinetic metal bending.Randi, J. (1983). The Project Alpha experiment: Part one: the first two years. ''Skeptical Inquirer'', Summer issue. Such methodological failures have been cited as evidence that most, if not all, extraordinary results in parapsychology derive from error or fraud.

Criticism of experimental results

Although some critical analysts feel that parapsychological study is scientific, they are not satisfied with its experimental results.
Skeptical reviewers contend that apparently successful experimental results in psi research are more likely due to sloppy procedures, poorly trained researchers, or methodological flaws than to genuine psi effects.{{cite paper |author=Akers, C. |title=Methodological Criticisms of Parapsychology, Advances in Parapsychological Research 4 |publisher=PesquisaPSI |date=1986 |url=http://www.pesquisapsi.com/books/advances4/7_Methodological_Criticisms.html
|accessdate=2007-07-30}}{{cite paper |author=Child, I.L.
|title=Criticism in Experimental Parapsychology, Advances in Parapsychological Research 5 |publisher=PesquisaPSI |date=1987 |url= http://www.pesquisapsi.com/books/advances5/6_Criticism_in_Experimental.html |accessdate=2007-07-30 }} For example, the data from the PEAR laboratory has been criticized by researchers such as statistics professor Jessica Utts and psychologist Ray Hyman. Utts has stated that these experiments suffered numerous problems with regard to randomization, statistical baselines and the application of statistical models, and that the significance values quoted in the experiments were meaningless due to defects in experimental and statistical procedures of the studies.

Because psi is a negatively defined concept, a typical measure of the evidence for such phenomena in parapsychological experiments is statistical deviation from chance expectation. However, critics point out that statistical deviation from chance is, strictly speaking, only evidence of a statistical anomaly, or that some unknown variable was causing the deviation from chance. Hyman contends that even if experiments could be made to reproduce the findings of certain parapsychological studies under specific conditions, this would be a far cry from concluding that psychic functioning has been demonstrated. It has also been stated that assuming psi exists is affirming the consequent or begging the question. Reasoning that (1) if a person is psychic, then that individual will do better than chance in experiments, and (2) since that person does better than chance, then, (3) that person must be psychic, would be considered the fallacy of affirming the consequent.

Selection bias and meta-analysis

Selective reporting has been offered by critics as an explanation for the positive results reported by parapsychologists. Selective reporting is sometimes referred to as a "file drawer" problem, which arises when only positive study results are made public, while studies with negative or null results are not made public. Selective reporting has a compounded effect on meta-analysis, which is a statistical technique that aggregates the results of many studies in order to generate sufficient statistical power to demonstrate a result that the individual studies themselves could not demonstrate at a statistically significant level. For example, a recent meta-analysis combined 380 studies on psychokinesis, including data from the PEAR lab. It concluded that, although there is a statistically significant overall effect, it is not consistent and relatively few negative studies would cancel it out. Consequently, biased publication of positive results could be the cause.

The popularity of meta-analysis in parapsychology has been criticized by numerous researchers, and is often seen as troublesome even within parapsychology itself. Critics have said that parapsychologists misuse meta-analysis to create the incorrect impression that statistically significant results have been obtained which indicate the existence psi phenomena.

Critical analysts also contend that the practice of meta-analysis is post hoc. The evaluation of the metholological quality of a study, after it is done and the results are known, can create opportunity for biases to affect the analyses. Various strategies, methods and criteria can be selected, which provide an opportunity for selecting outcomes that are consistent with the expectations of the analyst. It is not uncommon to find that two or more meta-analyses done at about the same time by investigators with the same access to the literature reach incompatible or even contradictory conclusions.Bailar, J.C. (1997). "The promise and problems of meta-analysis", ''New England Journal of Medicine'', 337, 559-561, cited in Kennedy, 2004, JoP 68

Organizations and publications

A number of university laboratories conduct parapsychological research. Among these are the Koestler Parapsychology Unit at the University of Edinburgh; the Parapsychology Research Group at Liverpool Hope University; the VERITAS Research Program at the University of Arizona; the Consciousness and Transpersonal Psychology Research Unit of Liverpool John Moores University; the Center for the Study of Anomalous Psychological Processes at the University of Northampton; and the Anomalistic Psychology Research Unit at Goldsmiths University of London. The Princeton Engineering Anomalies Research, a well-known laboratory that conducted psychokinesis experiments, closed in February 2007.

Research organizations include the Parapsychological Association; the Society for Psychical Research, publisher of the ''Journal of Society for Psychical Research''; the American Society for Psychical Research, publisher of the ''Journal of the American Society for Psychical Research''; the Rhine Research Center and Institute for Parapsychology, publisher of the ''Journal of Parapsychology''; the Parapsychology Foundation, publisher of the ''International Journal of Parapsychology''; and the Australian Institute of Parapsychological Research, publisher of the ''Australian Journal of Parapsychology''. The ''European Journal of Parapsychology'' is independently published.

Organizations that encourage a critical examination of parapsychology and parapsychological research include the Committee for Skeptical Inquiry, publisher of the ''Skeptical Inquirer''; and the James Randi Educational Foundation, founded by magician and skeptic James Randi.