Telepathy

===Ganzfeld experiment===
When using the [[Ganzfeld experiment]] to test for telepathy, one individual is designated as the receiver and is placed inside a controlled environment where they are [[sensory deprivation|deprived of sensory input]], and another person is designated as the sender and is placed in a separate location. The receiver is then required to receive information from the sender. The nature of the information may vary between experiments.<ref name="Conscious Universe">''The Conscious Universe: The Scientific Truth of Psychic Phenomena'' by Dean I. Radin Harper Edge, {{ISBN|0062515020}}</ref>

The Ganzfeld experiment studies that were examined by [[Ray Hyman]] and [[Charles Honorton]] had methodological problems that were well documented. Honorton reported only 36% of the studies used duplicate target sets of pictures to avoid handling cues.<ref>Julie Milton, [[Richard Wiseman]]. (2002). ''A Response to Storm and Ertel (2002)''. The Journal of Parapsychology. Volume 66: 183–186.</ref> Hyman discovered flaws in all of the 42 Ganzfeld experiments and to access each experiment, he devised a set of 12 categories of flaws. Six of these concerned statistical defects, the other six covered procedural flaws such as inadequate [[documentation]], randomization and security as well as possibilities of sensory leakage.<ref name="Hyman2007">[[Ray Hyman]]. ''Evaluating Parapsychological Claims'' in Robert J. Sternberg, Henry L. Roediger, Diane F. Halpern. (2007). ''Critical Thinking in Psychology''. Cambridge University Press. pp. 216–231. {{ISBN|978-0521608343}}</ref> Over half of the studies failed to safeguard against sensory leakage and all of the studies contained at least one of the 12 flaws. Because of the flaws, Honorton agreed with Hyman the 42 Ganzfeld studies could not support the claim for the existence of psi.<ref name="Hyman2007"/>

Possibilities of sensory leakage in the Ganzfeld experiments included the receivers hearing what was going on in the sender's room next door as the rooms were not soundproof and the sender's fingerprints to be visible on the target object for the receiver to see.<ref>[[Richard Wiseman]], Matthew Smith, Diana Kornbrot. (1996). ''Assessing possible sender-to-experimenter acoustic leakage in the PRL autoganzfeld''. Journal of Parapsychology. Volume 60: 97–128.</ref><ref>[[Robert Todd Carroll]]. (2014).                                  [http://www.skepdic.com/ganzfeld.html "Ganzfeld]" in [[The Skeptic's Dictionary]].</ref>

Hyman also reviewed the autoganzfeld experiments and discovered a pattern in the data that implied a visual cue may have taken place:

{{blockquote|The most suspicious pattern was that the hit rate for a given target increased with the frequency of occurrence of that target in the experiment. The hit rate for the targets that occurred only once was right at the chance expectation of 25%. For targets that appeared twice the hit rate crept up to 28%. For those that occurred three times it was 38%, and for those targets that occurred six or more times, the hit rate was 52%. Each time a videotape is played its quality can degrade. It is plausible then, that when a frequently used clip is the target for a given session, it may be physically distinguishable from the other three decoy clips that are presented to the subject for judging. Surprisingly, the parapsychological community has not taken this finding seriously. They still include the autoganzfeld series in their meta-analyses and treat it as convincing evidence for the reality of psi.<ref name="Hyman2007"/>}}

Hyman wrote the autoganzfeld experiments were flawed because they did not preclude the possibility of sensory leakage.<ref name="Hyman2007"/> In 2010, Lance Storm, Patrizio Tressoldi, and Lorenzo Di Risio analyzed 29 ganzfeld studies from 1997 to 2008. Of the 1,498 trials, 483 produced hits, corresponding to a hit rate of 32.2%. This hit rate is [[Statistical significance|statistically significant]] with p < .001. Participants selected for personality traits and personal characteristics thought to be psi-conducive were found to perform significantly better than unselected participants in the ganzfeld condition.<ref name=StormEtAl2010>
{{cite journal | url=http://www.psy.unipd.it/~tressold/cmssimple/uploads/includes/MetaFreeResp010.pdf | journal=Psychological Bulletin | date=July 2010 | title=Meta-Analysis of Free-Response Studies, 1992–2008: Assessing the Noise Reduction Model in Parapsychology | last1=Storm |first1=Lance |last2=Tressoldi |first2=Patrizio E. |last3=Di Risio |first3=Lorenzo | volume=136 | issue=4 | pages=471–85 | access-date=2010-08-18 | pmid=20565164 | doi=10.1037/a0019457 | url-status=dead | archive-url=https://web.archive.org/web/20110124055506/http://www.psy.unipd.it/~tressold/cmssimple/uploads/includes/MetaFreeResp010.pdf | archive-date=2011-01-24 }}</ref> Hyman (2010) published a rebuttal to Storm ''et al''. According to Hyman "reliance on meta-analysis as the sole basis for justifying the claim that an anomaly exists and that the evidence for it is consistent and replicable is fallacious. It distorts what scientists mean by confirmatory evidence." Hyman wrote the ganzfeld studies have not been independently replicated and have failed to produce evidence for telepathy.<ref>Hyman, R. (2010).                             [http://drsmorey.org/bibtex/upload/Hyman:2010.pdf ''Meta-analysis that conceals more than it reveals: Comment on Storm et al''] {{webarchive|url=https://web.archive.org/web/20131103081111/http://drsmorey.org/bibtex/upload/Hyman%3A2010.pdf |date=2013-11-03 }}. (2010). Psychological Bulletin, 136. pp. 486–490.</ref> Storm ''et al''. published a response to Hyman claiming the ganzfeld experimental design has proved to be consistent and reliable but parapsychology is a struggling discipline that has not received much attention so further research on the subject is necessary.<ref>{{cite journal | last1 = Storm | first1 = L. | last2 = Tressoldi | first2 = P. E. | last3 = Di Risio | first3 = L. | year = 2010 | title = A meta-analysis with nothing to hide: Reply to Hyman (2010) | journal = Psychological Bulletin | volume = 136 | issue = 4| pages = 491–494 | doi=10.1037/a0019840| pmid = 20565166 | s2cid = 21103309 }}</ref> Rouder ''et al''. 2013 wrote that critical evaluation of Storm ''et al''.'s meta-analysis reveals no evidence for telepathy, no plausible mechanism and omitted replication failures.<ref>{{cite journal | last1 = Rouder | first1 = J. N. | last2 = Morey | first2 = R. D. | last3 = Province | first3 = J. M. | year = 2013 | title = A Bayes factor meta-analysis of recent extrasensory perception experiments: Comment on Storm, Tressoldi, and Di Risio (2010) | journal = Psychological Bulletin | volume = 139 | issue = 1| pages = 241–247 | doi=10.1037/a0029008| pmid = 23294092 }}</ref> A 2016 paper examined questionable research practices in the ganzfeld experiments.<ref>{{citation|title=Testing for Questionable Research Practices in a Meta-Analysis: An Example from Experimental Parapsychology|last1=Bierman|first1=DJ|last2=Spottiswoode|first2=JP|last3=Bijl|first3=A|year=2016|journal=PLOS ONE|volume=11|issue=5|page=1|doi=10.1371/journal.pone.0153049|quote=We consider [questionable research practices] in the context of a meta-analysis database of Ganzfeld–telepathy experiments from the field of experimental parapsychology. The Ganzfeld database is particularly suitable for this study, because the parapsychological phenomenon it investigates is widely believed to be nonexistent.|pmid=27144889|pmc=4856278|bibcode=2016PLoSO..1153049B|doi-access=free}}</ref>