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Meta-analysis of experiments on remote intentions using electrodermal activity
Abstract
Findings in parapsychology suggest an effect of distant intentionality. Two laboratory setups explored this topic by measuring the effect of a distant intention on psychophysiological variables. The 'Direct Mental Interaction in Living Systems' experiment investigates the effect of various intentions on the electrodermal activity of a remote subject. The 'Remote Staring' experiment examines whether gazing by an observer covaries with the electrodermal activity of the person being observed. Two meta-analyses were conducted. A small significant effect size ðd ¼ :11; p ¼ :001Þ was found in 36 studies on 'direct mental interaction', while a best-evidence-synthesis of 7 studies yielded d ¼ :05 ð p ¼ :50Þ: In 15 remote staring studies a mean effect size of d ¼ 0:13 ðp ¼ :01Þ was obtained. It is concluded that there are hints of an effect, but also a shortage of independent replications and theoretical concepts.
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In most of the direct mental interactions with living systems (DMILS)/Remote Staring studies, electrodermal activity (EDA) is the only dependent variable. Therefore the quality of EDA recording is crucial. This is the reason why we studied EDA-related literature and contacted some of the leading psychophysiological labs in Germany to debate critical topics of the EDA measurement. We also checked the Methods section of all studies using EDA data published from 1995 to 1999 in the leading psychophysiological journals. In addition, we surveyed all DMILS/Remote Staring publications using EDA to find out whether parapsychologists adhere to these standards. In the first part of our paper we outline a current state-of-the-art EDA methodology. We also address various technical problems and describe sources for potential artifacts. In the second part we compare 24 DMILS/Remote Staring with a sample of 39 recent psychophysiological studies published in Psychophysiology and International Journal of Psychophysiology. The analysis reveals that parapsychologists do not meet the current standards. There is not even one study conducted by parapsychologists which refers to psychophysiology's measurement standards published in 1981. Therefore, DMILS/Remote Staring data may either contain artifacts, or, on the other hand, may not detect the supposed effects. Although there is an ongoing trend of finding irregularities in EDA data of DMILS/Remote Staring experiments that can be related to different intentional conditions, there have not been any efforts to understand the results of EDA experiments or to address the origin of the irregularities in detail.
Reactions to an Unseen Gaze (Remote Attention):
A Review, with New Data on Autonomic Staring Detection
The Journal of Parapsychology
Braud, William, Shafer, Donna, Andrews, Sperry
Have you ever had the feeling that someone was staring at you from behind and, upon turning around, found you were correct? From time to time, most of us have had such a feeling, which appears to be a common part of the human experience. In surveys conducted in California (Coovet, 1913) as early as 1913, 68% to 86% of respondents reported having had the feeling of being watched or stared at on at least one occasion, and a more recent Australian survey (Williams, 1983) placed the figure at 74%. In a survey of San Antonio respondents recently completed as part of the present project, the figure was found to be approximately 94%. Despite its widespread occurrence and familiarity, the staring experience has been subjected to surprisingly little scientific scrutiny. Is the presumed ability to detect an unseen gaze merely a superstition, a cultural myth without real substance, an overinflation of coincidental occurrences, or a response to subtle sensory cues? Or, alternatively, could the experience be a valid indicator of an exceptional yet poorly understood human capability?
4/22/2017Further Studies of Autonomic Detection of Remote Staring: Replication, New Control Procedures, and Personality Correlates" by Braud, William, Shafer, Donn...https://www.questia.com/read/1G1-15667545/further-studies-of-autonomic-detection-of-remote-staring1/19Further Studies of Autonomic Detection of Remote Staring:Replication, New Control Procedures, and PersonalityCorrelatesBy Braud, William; Shafer, Donna et al.The Journal of Parapsychology, December1993Further Studies of Autonomic Detection ofRemote Staring: Replication, New ControlProcedures, and Personality CorrelatesBraud, William, Shafer, Donna, Andrews, Sperry, The Journal of ParapsychologyIn a previous paper (Braud, Shafer, & Andrews, 1993), we reviewed the scientific litera-ture dealing with the purported ability to detect when one is being watched or stared at bysomeone situated beyond the range of the conventional senses. Surveys indicated that be-tween 68% and 94% of various samples reported having had staring detection experiencesin their everyday lives. Previous investigations provided suggestive evidence that personswere indeed able to detect, consciously, when they were being stared at under conditionsin which precautions were taken to eliminate possible subtle sensory cues. In particular,positive conscious-guessing results were obtained in two studies in which sensory cueingwas eliminated through use of one-way mirrors (Peterson, 1978) and use of a closed-cir-cuit television system (Williams, 1983).We hypothesized that stronger effects might be obtained if relatively "unconscious" auto-nomic nervous system activity were used as the indicator of staring detection, rather thanconscious guessing. Our reasoning was that autonomic reactions might be less distortedby higher cognitive processes and therefore might provide a purer and more sensitive in-dicator. We presented the results of two original experiments in which sympathetic ner-vous system activation was assessed by means of electrodermal monitoring during ran-
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4/22/2017Further Studies of Autonomic Detection of Remote Staring: Replication, New Control Procedures, and Personality Correlates" by Braud, William, Shafer, Donn...https://www.questia.com/read/1G1-15667545/further-studies-of-autonomic-detection-of-remote-staring2/19domly interspersed remote-staring and nonstaring (control) periods. The monitored par-ticipant was unaware of the number, timing, or scheduling pattern of these two types ofperiods. The possibility of sensory cueing was eliminated through the use of a closed-cir-cuit television system for staring: the starer devoted full attention to the staree's image onthe television monitor. In the first experiment, 16 untrained participants evidenced signif-icant autonomic discrimination, becoming more activated during staring than duringnonstaring periods. In the second experiment, 16 subjects who had been extensivelytrained to become more aware of their interconnections with other people and less defen-sive about their connectedness also evidenced significant autonomic discrimination, butbecame more calm during staring than during nonstaring periods; the starer had beensimilarly trained. As judged by effect sizes, unconscious autonomic detection did indeedappear to yield stronger effects than did previous conscious verbal or motoric detectionassessments.In the present paper, we present our attempts to replicate and extend our previous find-ings. Identical equipment, basic procedures, and analysis methods were used. The firstreplication involved 3 new starers and 30 new starees. The second replication involved thesame starer who had participated in the earlier experiments reported in 1993, but em-ployed 16 new starees. We made two additions in these studies. One of these was the in-troduction (into Replication 2) of an additional empirical control condition. This was a"sham control" in which we treated sessions and data as we did for real staring sessions,but staring did not, in fact, occur; this provided an empirical assessment of the likelihoodof obtaining chance discriminations of otherwise equivalent session segments. The secondimprovement was the introduction of a new personality assessment for the starees in bothreplications. In addition to the Myers-Briggs Type Inventory (MBTI) we had been using inthe original studies, we included an assessment of social anxiety or discomfort in a socialsituation (a Social Avoidance and Distress scale), in order to explore the possible interre-lationships of these personality characteristics with the autonomic staring detectioneffect.METHODSubjects
(4) (PDF) Further studies of autonomic detection of remote staring: Replication, new control procedures, and personality correlates. Available from: https://www.researchgate.net/publication/284061135_Further_studies_of_autonomic_detection_of_remote_staring_Replication_new_control_procedures_and_personality_correlates [accessed Feb 06 2019].
Meta-analysis collects and synthesizes results from individual studies to estimate an overall effect size. If published studies are chosen, say through a literature review, then an inherent selection bias may arise, because, for example, studies may tend to be published more readily if they are statistically significant, or deemed to be more “interesting” in terms of the impact of their outcomes. We develop a simple rank-based data augmentation technique, formalizing the use of funnel plots, to estimate and adjust for the numbers and outcomes of missing studies. Several nonparametric estimators are proposed for the number of missing studies, and their properties are developed analytically and through simulations. We apply the method to simulated and epidemiological datasets and show that it is both effective and consistent with other criteria in the literature.
_Journal of the Society for Psychical Research 62: 311-323 (1998)_ Simple experiments to test whether or not people can tell when they are being stared at from behind were carried out in schools in Germany and the United States. Lookers and subjects worked in pairs, with the lookers sitting behind the subjects. In a series of trials the lookers either looked or did not look at the subjects in a random sequence determined by tossing a coin. In each trial, the subjects guessed whether or not they were being looked at. The results show an overall positive effect, with 56.9% correct guesses as opposed to 50% expected by chance. 97 of the subjects were right more often than they were wrong, and 42 were wrong more often than they were right. This positive effect was highly significant statistically (p=3x10-6). The data showed a consistent pattern. There was a positive effect when the subjects were being looked at, while the guesses were not significantly different from chance when they were not being looked at. In one school in Germany where sensitive subjects were tested repeatedly, 71.2% of the guesses were correct, and two students were right about 90% of the time. Possible sources of artefacts in these experiments are examined, and the implications of the results are discussed.
The sense of being stared at from behind can be investigated by means of simple experiments in which subjects and lookers work in pairs, with the looker sitting behind the subject. In a random sequence of trials the looker either looks at the back of the subject, or looks away and thinks of something else. In each trial the subject guesses whether or not he or she is being looked at. There is a 50% probability of getting it right by chance. More than 15,000 trials have already been conducted, involving more than 700 subjects, with extremely significant excess of correct over incorrect guesses (Sheldrake, 1999), indicating that people really can tell when they are being looked at from behind. In this paper I discuss possible artifacts that could have affected these results and describe the results of experiments carried out in a school in London in which I investigated the effects of blindfolding subjects and giving them feedback about whether their guesses were correct or not. Blindfolding and feedback had no significant effects. Under all conditions the scores in looking trials were positive and statistically significant, and in not-looking trials at chance levels. I also describe the results of a series of experiments carried out in schools in Ireland with blindfolded subjects who were not given feedback. The significant positive scores in these experiments confirmed that the feeling of being stared at from behind does not depend on visual clues, nor does it depend on the subjects knowing if their guesses are right or wrong.
The feeling of being stared from behind is well known all over the world, and most people claim to have experienced it themselves. There have been surprisingly few empirical investigations of this phenomenon. I describe a simple experimental procedure with subjects and lookers working in pairs. In a random sequence of trials, the looker either looked at the back of the subject, or looked away and thought of something else. Such experiments showed a very significant excess of correct over incorrect guesses. When subjects were being looked at, they guessed correctly about 60% of the time, whereas in control trials, when they were not being looked at, their guesses were close to the chance level of 50%. The same pattern of results was found in my own experiments with adult subjects, with two different procedures: in experiments conducted in schools in Connecticut, USA; in experiments conducted by volunteers all around the world; and in a previous series of experiments in schools in Germany and the USA. All these sets of data showed a highly significant effect. Taken together they showed that in looking trials,. 427 people were more often right than wrong, as opposed to 157 who were more often wrong than right. This difference is extremely significant (p < 1 × 10-25). In the control trials, there was no significant difference between the number of people who were more often right than wrong (294) and more often wrong than right (287). These results suggest that the feeling of being looked at from behind is a real phenomenon that depends on factors as yet unknown to science. Non-human animals may also share this kind of sensitivity, which may be of evolutionary significance in the relationships between predators and prey.
Scientific progress is achieved not only by continuous accumulation of knowledge but also by paradigm shifts. These shifts are often necessitated by anomalous findings that cannot be incorporated in accepted models. Two important methodological principles regulate this process and complement each other: Ockham's Razor as the principle of parsimony and Plato's Life Boat as the principle of the necessity to 'save the appearances' and thus incorporate conflicting phenomenological data into theories. We review empirical data which are in conflict with some presuppositions of accepted mainstream science: Clinical and experimental effects of prayer and healing intention, data from telepathy, psychokinesis experiments and precognition, and anecdotal reports of macro-psychokinesis. Taken together, the now well documented possibility of these events suggests that such phenomena are anomalies that challenge some widely held beliefs in mainstream science. On the other hand, scientists often fear that by accepting the reality of these phenomena they also have to subscribe to world-models invoking ontological dualism or idealism. We suggest accepting the phenomena as real, but without questionable ontologies commonly associated with them. We outline how this might work.
The "sense of being stared at" can be investigated by means of simple experiments in which subjects and lookers work in pairs, with the looker sitting behind the subject. In a random sequence of trials, the looker either looks at the back of the subject, or looks away and thinks of something else. More than 15,000 trials have already been conducted, involving more than 700 subjects, with an extremely significant excess of correct over incorrect guesses (Sheldrake [1999]). This effect was still apparent in experiments in which subjects were blindfolded and given no feedback, showing it did not depend on visual clues, nor on the subjects knowing if their guesses were right or wrong (Sheldrake [2000]). In this paper I describe experiments I conducted in schools in England in which the subjects were not only blindfolded and given no feedback, but looked at through closed windows. There was again a very significant excess of correct over incorrect guesses (p < 0.004). At my request, schoolteachers in Canada, Germany and the United States carried out similar experiments and found an even more significant positive effect than in my own experiments (p < 0.0002). The fact that positive results were still obtained when visual clues had been effectively eliminated by blindfolds, and auditory and olfactory clues by closed windows, implies that the sense of being stared at does not depend on the known senses. I conclude that peoples' ability to know when they are being looked at depends on an influence at present unknown to science.
This paper provides definitions and a discussion of evolving guidelines for conducting research on the effects of distant healing intention (DHI) on living systems in the laboratory. We consider the relevance of DHI laboratory research to applied healing, special theoretical challenges, and other considerations that distinguish DHI research from other domains of laboratory science. Two sample protocols for investigating DHI are provided, one involving the human autonomic nervous system as the "target" of distant intention, and the other involving cell cultures. In essence, DHI differs from other alternative healing modalities because it postulates that mental intention alone can affect living systems at a distance, unbounded by the usual constraints of both space and time. This postulate challenges scientific assumptions that often go unexamined, including the nature of causality, the distinction between subjective and objective states, and the efficacy of double-blind protocols in controlling for experimenters' intentions. Previous laboratory research in this domain suggests that DHI effects warrant serious study, but most scientists and funding agencies are unaware of the evidence or the relevant literature. By following these evolving guidelines, researchers' designs and their ultimate publications will conform more closely to the quality standards expected by scientific journals, and such publications will in turn attract the attention of a broader range of scientists. This seems especially important for alternative healing research in general and for distant healing in particular; both realms enjoy broad public support but have largely eluded serious attention by mainstream science.
This article addresses methodological issues in current EDA-DMILS research. The authors conducted an exploratory DMILS pilot study with 26 sessions and found a medium size effect, No significant psi finding is claimed, as the experiment was not designed to find or investigate any; instead, the authors studied the variation of this effect as a function of different methodological approaches. They compared different EDA parameters (tonic or phasic) and found effects similar in size. Furthermore, they contrasted the traditional parapsychological way to parameterize data with methods adapted from psychophysiological research, These new parameters clearly outperformed the parameter used so far in DMILS/Remote Staring research. Respiration is correlated with the electrodermal system. The authors investigated whether EDA. responses that are caused by sudden irregular patterns in breathing are also part of the remote intention effect. Therefore, they discarded all these responses from the data. The effect size dropped down to 30%-77% (depending on the parameter) of its original value. This indicates that the remote intention effect is very likely to also affect the pulmonary system. Finally, they compared different statistical methods for the evaluation of EDA-DMILS data and show the traditional percentage influence score method is neither appropriate nor suitable. The authors present alternative methods, and compare their power using the pilot study data.
It is a truism that our mental processes can exert profound influences upon our own bodies, upon other people, and upon the physical world. I intend to wiggle my finger, and the finger obliges. I wish to move from one room to another, and the complex system of my musculature cooperates and takes me there. I intend to remember a particular event that occurred when I was five years old, and my memory recalls that scene for me and presents it to me in vivid detail. These interactions of mental processes such as intentions, volitions, purposes, aims, and wishes with our own physical bodies are familiar to all of us; we take them for granted and rarely give them a second thought. Similarly commonplace are the many influences of our intentions upon the external physical world. I intend to build a stone house, and after a while it appears in the landscape, where it may remain for centuries as a physical embodiment of my intention. I intend to save a continent of children from the ravages of a particular disease, develop an effective vaccine, innoculate thousands of children, and hundreds of lives are saved. As a scientist, my intentions and wishes lead me to conceive and carry out specific types of experiments, test specific hypotheses, and construct particular theories. M y intentions influence what I choose to study, how I study it, the types of observations I make, and the interpretations I prefer. The outcomes of these studies can have important impacts upon our understanding of the physical world and may have dramatic impacts upon the physical world itself. All of these influences, although they can be quite dramatic, are indirect. The influences of intention within my own body are typically understood as effects mediated by systems of anatomical, neurohormonal, and biochemical pathways. Intentional influences upon the external physical world are mediated by my bodily reactions and words and through persons and objects in my vicinity. One can ask, however, whether there might be special instances in which our intentions can have more direct, unmediated influences upon the physical world. Throughout history, there have been beliefs that, under certain conditions, such influences are possible, and there is indeed of body of anecdotal and laboratory evidence that suggests that direct intentional influences upon the physical world can indeed occur. Such influences have been described as "mind over matter" effects and are also known by their aliases, "telekinesis" and "psychokinesis". M ore recently, they have been termed "remote action" and "anomalous perturbation" effects. I prefer to call them, simply, "direct mental interactions".
Previous research by Schwartz et al. (1995) documented that subjects could correctly guess, above chance, the presence of an experi-menter's hand placed a few inches above one of their hands in the absence of visual and auditory information. Were subjects detecting the biophysical energy of the experimenter's hands and/or the intention of the experi-menters? The present experiments employed a different interpersonal regis-tration paradigm and examined whether individual differences in detection accuracy were related to experiences with subtle interpersonal registration (interpersonal ESP and survival of consciousness experiences). In Experi-ment 3, 20 male and 20 female subjects received 32 trials of actual eye gazes and intended eye gazes. Subjects sat with their backs to the experimenters. The 2 design (head/back by actual/intended gaze) used a counterbalanced order. At the end of the experiment, subjects estimated their correct guesses and also rated their openness to spiritual beliefs and experiences. Percent correct detections for actual stares was 56% (p < .003); percent correct detections for intended stares was 60% (p < .001). There was no correlation between subjects' estimates of their performance and their actual perfor-mance. However, subjects' responses to the questions such as "have you ever experienced 'ESP' between people such as connected with a loved one from a distance or having a predictive dream about someone?" and "have you ever experienced the presence of someone who has passed away?" were each significantly corrected with their accuracy in detecting actual and intended eye gaze (r = .47, p < .002; r = .40, p < .01). These findings suggest that inter-personal sensitivity may be related to implicit registration of individuals in physical and energy systems. Since subtle auditory and other cues may have been involved in these studies, future studies should examine various sources of possible information and energy cues in this paradigm.
Advances in science and technology are generally the product of multiple investigations. This article discusses statistical methods for combining empirical results from a series of different experiments or clinical investigations. We delineate the steps an assessor might take in combining data from different studies and provide references for topics not discussed in detail. The article reviews some of the most commonly used statistical techniques for combining results in the medical and social sciences.
The expression meta-analysis refers to the practice of using statistical methods to combine the outcomes of a series of different experiments or investigations. The terminology arises because a meta-analysis uses a study as the unit of observation, and, thus, the data point for each study is itself a statistical summary based on an analysis of primary data.
A new type of research, termed meta-analysis, attempts to analyze and combine the results of previous reports. We found 86 meta-analyses of reports of randomized controlled trials in the English-language literature. We evaluated the quality of these meta-analyses, using a scoring method that considered 23 items in six major areas--study design, combinability, control of bias, statistical analysis, sensitivity analysis, and application of results. Only 24 meta-analyses (28 percent) addressed all six areas, 31 (36 percent) addressed five, 25 (29 percent) addressed four, 5 (6 percent) addressed three, and 1 (1 percent) addressed two. Of the 23 individual items, between 1 and 14 were addressed satisfactorily (mean +/- SD, 7.7 +/- 2.7). We conclude that an urgent need exists for improved methods in literature searching, quality evaluation of trials, and synthesizing of the results.
Research review has long been one of the most important scholarly activities in all branches of science. While there is sometimes a single study so well-designed, well carried out, and difficult to replicate that its findings are accepted as conclusive, more often there are many studies on a given topic, no one of which clearly supersedes the others. These studies may be done by different investigators using different methods or different populations. They may arrive at different conclusions. When this is the case, there is a need for reviewers to carefully consider the evidence and to put forth conclusions or hypotheses about where the weight of the evidence lies.
Conclusions about the efficacy and safety of medical interventions are based on data presented in the scientific literature. The validity of these conclusions is threatened if publication bias results from investigators or editors making decisions about publishing study results on the basis of the direction or strength of the study findings. This paper reports meta-analyses performed using data from four prospective investigations in which a total of 997 initiated studies were followed to learn of study results, publication status, and reasons for nonpublication. The analysis indicates that there is a positive association between "significant" study results and publication (OR = 2.88; 95% confidence interval [CI] 2.13 to 3.90). When the analysis was restricted to controlled trials (n = 280), an even stronger relationship between "significant" results and publication was observed (OR = 6.15; 95% CI 2.24 to 16.92), with randomized trials (n = 200) apparently no less susceptible to publication bias than controlled trials in general (OR = 8.72; 95% CI 1.91 to 39.81). In every case, failure to publish was investigator-based, and not due to editorial decisions. The results of clinical trials should not be suppressed in this way. Development of registration systems for randomized trials is essential if this problem is to be minimized in future.
Since the 1950s, researchers have attempted to understand reports of distant or "psychic" healing, developing experimental protocols that test the distant healing hypothesis by measuring biological changes in a target system while ruling out suggestion or self-regulation as counterexplanations. This article provides a brief overview of these "healing analog" experiments. It also provides a summary and meta-analysis of 30 formal experiments in which self-reported healers, "psychics," and other self-selected volunteers attempted to influence autonomic nervous system activity in a distant person. Results across the experiments showed a significant and characteristic variation during distant intentionality periods, compared with randomly interspersed control periods. Possible alternative explanations for the reported effects are considered. Finally the implications of distant intentionality are discussed for an understanding of the possible mechanisms of distant healing, the nature of the mind-body relationship, and the role of consciousness in the physical world.
There is evidence to suggest that individuals not only believe in their ability to detect an unseen gaze, but may genuinely be able to do so. The present study reviewed past research and sought to determine whether such a phenomenon was empirically demonstrable. In Expt 1, 12 participants responded to 12 sequences (with feedback in the last nine) of 20 trials each, with staring or non-staring episodes based on Sheldrake's random number sequences. No effects were obtained when no feedback was given. With feedback, more accurate than mean chance expectation (MCE) results were obtained on staring, but no difference on non-staring trials. However other 'normal' explanations of ESP phenomena discuss the possibility of matching in bias between experimental sequences and participants' representations of randomness. Tests of the sequences found more alternations than expected, a feature typical of subjective randomness, but the increase in accuracy found on staring trials only was not consistent with this explanation. It was concluded that the improvement in accuracy with feedback is likely to be due to implicit learning, given the structure in non-random sequences. This hypothesis was supported in Expt 2 where 12 participants responded to 12 'genuinely random' sequences, and no differences in accuracy from MCE were obtained.
Meta-analysis (MA) is the application of quantitative techniques for the purposes of summarizing data from individual studies. This type of review has many advantages over traditional reviews. However, different investigators performing MAs on the same data set have reached different conclusions. These reliability problems have been attributed to differences in the quality of the implemented meta-analytic procedures. We, therefore, examined the chronic pain treatment meta-analytic literature for MA procedure quality and for the consistency of conclusions. DESIGN, SETTING, PARTICIPANTS, OUTCOME MEASURES: Chronic pain treatment MAs were isolated according to inclusion/exclusion criteria. Data from these MAs were abstracted into structured tables. Table format reflected eight meta-analytic procedures identified previously as being important to MA implementation quality. These were: adequacy of retrieval, publication bias, inclusion/exclusion criteria, abstraction of data, quality, homogeneity/heterogeneity, independence, and statistical versus clinical interpretation. Each meta-analytic procedure was then independently rated by two raters. Rating results were then analyzed by procedure for each individual MA for percentage scores out of 100%, and mean scores. For MAs addressing the same topic area (pain facility treatment, antidepressant treatment, manipulation treatment) direction of effect size was noted. Mean effect sizes were calculated for these subgroups.
Sixteen chronic pain treatment MAs fulfilled inclusion/exclusion criteria. Mean procedure ratings indicated that four procedures may not be implemented adequately. These were publication bias, abstraction of data, quality, and homogeneity/heterogeneity. There was wide MA implementation score variability, with 37.5% scoring less than 50%. The effect sizes of the MA subgroups demonstrated replicate nonvariability.
Some meta-analytic procedures could be interpreted to be implemented inadequately in some chronic pain treatment MAs. There is wide variability between individual chronic pain treatment MAs on adequacy of implementation of these procedures. However, the effect sizes of the different MA subgroups demonstrated consistency. This finding indicates that for these MA subgroups, MA results are consistent between authors. In addition, chronic pain MAs, as compared with other groups of MAs, appear to address some of the procedures in a more adequate fashion. Future chronic pain MAs should concentrate on improving the quality of their methods with particular emphasis on the above four procedures. Because of potential validity problems with these results, these data cannot and should not be used to make administrative decisions about previous MAs.
Meta-analyses are subject to bias for many of reasons, including publication bias. Asymmetry in a funnel plot of study size against treatment effect is often used to identify such bias. We compare the performance of three simple methods of testing for bias: the rank correlation method; a simple linear regression of the standardized estimate of treatment effect on the precision of the estimate; and a regression of the treatment effect on sample size. The tests are applied to simulated meta-analyses in the presence and absence of publication bias. Both one-sided and two-sided censoring of studies based on statistical significance was used. The results indicate that none of the tests performs consistently well. Test performance varied with the magnitude of the true treatment effect, distribution of study size and whether a one- or two-tailed significance test was employed. Overall, the power of the tests was low when the number of studies per meta-analysis was close to that often observed in practice. Tests that showed the highest power also had type I error rates higher than the nominal level. Based on the empirical type I error rates, a regression of treatment effect on sample size, weighted by the inverse of the variance of the logit of the pooled proportion (using the marginal total) is the preferred method.
Robert Baker replies to Sheldrake
- R A Baker
Baker, R. A. (2001). Robert Baker replies to Sheldrake. Skeptical Inquirer, 25, 61.
Empirische Testung der Theorie der morphischen resonanz -Können wir entdecken wenn wir angeblickt werden? Kommentar [Empirical test of the theory of morphic resonance -Dowe feel if somebody is staring at us?
- S Schmidt
Schmidt, S. (2001). Empirische Testung der Theorie der morphischen resonanz -Können wir
entdecken wenn wir angeblickt werden? Kommentar [Empirical test of the theory of morphic
resonance -Dowe feel if somebody is staring at us?].
Judging research quality
- P M Wortman
Wortman, P. M. (1994). Judging research quality. In H. Cooper, & L. V. Hedges (Eds.), The
handbook of research synthesis (pp. 97 -109). New York: Rusell Sage Foundation.
Außergewöhnliche Kommunikation? Eine kritische Evaluation des parapsychologischen Standardexperimentes zur direkten mentalen Interaktion [Extraordinary communication? A critcal evaluation of the parapsychological experiment on distant mental interaction
- S Schmidt
Schmidt, S. (2002). Außergewöhnliche Kommunikation? Eine kritische Evaluation des
parapsychologischen Standardexperimentes zur direkten mentalen Interaktion [Extraordinary communication? A critcal evaluation of the parapsychological experiment on distant
mental interaction]. Oldenburg: Bibliotheks-und Informationssystem der Universität.
Fooling and falling into the feeling of being stared at
- D Marks
- J Colwell
Marks, D., & Colwell, J. (2001). Fooling and falling into the feeling of being stared at. Skeptical
Inquirer, 25, 62 -63.
Systematic coding for research synthesis
- W A Stock
Stock, W. A. (1994). Systematic coding for research synthesis. In H. Cooper, & L. V. Hedges (Eds.),
The handbook of research synthesis (pp. 125-138). New York: Rusell Sage Foundation.
Combining estimates of effect size The handbook of research synthesis
- W R Shadish
- C K Haddock
Shadish, W. R., & Haddock, C. K. (1994). Combining estimates of effect size. In H. Cooper, &
L. V. Hedges (Eds.), The handbook of research synthesis (pp. 261-281). New York: Russell
Sage Foundation.
Evaluating coding decisions The handbook of research synthesis
- R A Orwin
Orwin, R. A. (1994). Evaluating coding decisions. In H. Cooper, & L. V. Hedges (Eds.),
The handbook of research synthesis (pp. 139-161). New York: Russell Sage Foundation.
Healing, intention and energy medicine: Research and clinical implications
- S Schmidt
Schmidt, S. (2003). Direct mental interaction with living systems (DMILS). In W. B. Jonas, &
C. C. Crawford (Eds.), Healing, intention and energy medicine: Research and clinical
implications (pp. 23 -38). Edinburgh: Churchill Livingstone.