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ERIC Number: EJ889650
Record Type: Journal
Publication Date: 2010-Jul
Pages: 15
Abstractor: As Provided
Reference Count: 103
ISSN: ISSN-0033-2909
Meta-Analysis of Free-Response Studies, 1992-2008: Assessing the Noise Reduction Model in Parapsychology
Storm, Lance; Tressoldi, Patrizio E.; Di Risio, Lorenzo
Psychological Bulletin, v136 n4 p471-485 Jul 2010
We report the results of meta-analyses on 3 types of free-response study: (a) ganzfeld (a technique that enhances a communication anomaly referred to as "psi"); (b) nonganzfeld noise reduction using alleged psi-enhancing techniques such as dream psi, meditation, relaxation, or hypnosis; and (c) standard free response (nonganzfeld, no noise reduction). For the period 1997-2008, a homogeneous data set of 29 ganzfeld studies yielded a mean effect size of 0.142 (Stouffer Z = 5.48, p = 2.13 x 10[superscript -8]). A homogeneous nonganzfeld noise reduction data set of 16 studies yielded a mean effect size of 0.110 (Stouffer Z = 3.35, p = 2.08 x 10[superscript -4]), and a homogeneous data set of 14 standard free-response studies produced a weak negative mean effect size of -0.029 (Stouffer Z = -2.29, p = 0.989). The mean effect size value of the ganzfeld database were significantly higher than the mean effect size of the nonganzfeld noise reduction and the standard free-response databases. We also found that selected participants (believers in the paranormal, meditators, etc.) had a performance advantage over unselected participants, but only if they were in the ganzfeld condition. (Contains 4 footnotes, 1 table, and 3 figures.)
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Publication Type: Journal Articles; Reports - Research
Education Level: N/A
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A