Ganzfeld experiment Methodological issues related to the study of ESP

Homework Read pages 2-4 of Anomalistic pack on coincidence. Answer the questions Due: 26 January

Starter Outline two differences between science and pseudoscience. (4 marks)

Pseudoscience actually means ‘false science’. Pseudoscientific explanations can be difficult to identify because they are presented as being scientific even though they do not meet the criteria for true science. Scientific findings are subjected to peer review before publication. Results of pseudoscience are published without peer review often in newspapers Science requires that experiments should be replicable but the results of many pseudoscientific studies cannot be replicated In science, key terms are defined precisely but in pseudoscience, specialist terms (eg ‘aura’) are used vaguely and not clearly operationalised

Ganzfeld experiment

What is ESP? What is the Ganzfeld experiment?

ESP: Ability to acquire knowledge and information without the use of the five main senses or previous experiences (e.g. telepathy, pre-cognition, clairvoyance etc). Ganzfeld: German word meaning ‘ total field’ and the name of the method used by anomalistic psychologists to examine ESP.

Findings from Ganzfeld

Meta-Analysis of Ganzfeld Studies Milton and Wiseman (1999) Published a meta-analysis of 30 ganzfeld studies carried out in seven independent laboratories according to stringent guidelines: – Strict security guidelines against sensory leakage – Testing and documentation of randomization methods for selecting targets and sequencing the judging pool – Statistical correction for multiple analyses – Advance specification of the status of the experiment (pilot testing) – Full documentation in the published report of the experimental procedures – The status of statistical tests These guidelines were put forward by Hyman and Honorton (1986)

Meta-Analysis of Ganzfeld Studies Milton and Wiseman’s data set consisted of 1198 individual trials Participants were found NOT to score above chance expectation (this means that their scores were found to be no more significant than guesswork!)

However The cut off date for studies to be completed was Feb 1997 This meant that one large-scale study with positive results was not included in the meta-analysis If it had been included, the results of the meta-analysis would have reached statistical significance (the results would not have been due to chance but due to an influence of the IV on the DV) The conditions required to establish a reliably positive outcome in ganzfeld studies have yet to be specified.

Criticisms of Ganzfeld research Hyman (1985) conducted a Meta-analysis of 42 pieces of research (48% of all the Ganzfeld research). He argued there was not enough evidence to support the existence of ESP due to flaws in the research: – Security – Statistical analysis (eg: data being missed out or incorrectly analysed) – Procedure

Criticisms cont. Milton & Wiseman’s (1999) MA suggested Ganzfeld studies are flawed as exact replication of procedures by peer research is impossible. However, Bem et al. (2001) conducted a MA using the same data as above and found a hit rate of 30% - statistically significant above the 25% expected. Endersby suggests we should be wary of using MA’s to examine the effects of ESP as they are prone to missing out data! File draw effect

Findings from Ganzfeld Read the findings now in your pack… – Honorton (1978) – Milton and Wiseman – Bem and Honorton – Hyman (1985) Note at the bottom of your pack what this suggests about the theory Try to make three points

Evaluation of studies 1. Why is it difficult to discount the notion that ESP exists? (use relevant terminology) 2. What may the variation in results tell us about the replicability of the Ganzfeld procedures used in the studies?

Methodological issues 1.Lack of Control 2.Non-randomisation of targets 3.Problems with the Ganzfeld procedure 4.Problems with statistical analysis

Can the choice of experimental design affect results? Differences between forced choice and free response. Honorton & Ferrari – 52yr Meta-analysis ESP in specially selected people (Forced Choice). Sig results. Milton – ESP in specially selected people (Free association – greater with Ganzfeld) But… File draw effect

Exam question Outline and evaluate the Ganzfeld technique as a way of investigating ESP. (4 marks + 4 marks)

Describe The sensory deprivation of a subject (the receiver) via headphones with white noise, translucent goggles or halved ping-pong balls over the eyes The sender, who is in another room, chooses one of a selection of (usually) 4 images to send telepathically. The choice of image to send should be random The receiver attempts to ‘read’ the image At the end of the session the receiver is shown a set of images and asked to select the target image from several or to describe the image If the receiver is really able to read the thoughts of others, he/she should be able to pick the target at greater than chance level over several trials

Evaluate AO2/AO3 credit is awarded for an evaluation of the Ganzfeld procedure as a way of studying ESP. Credit should be awarded for any relevant methodological issues including: – possible cheating and lack of control in early studies eg sensory leakage, insecure storage of images – possible researcher bias eg sceptical researchers v psi believers can influence the amount of elaboration by the receiver – influence of the receivers’ beliefs (the sheep-goat effect) Candidates may also consider how early problems led to the development of the auto-Ganzfeld procedure and discuss how this is an improvement on the original. This material