2. HISTORY
oParanormal ability claims have been scientifically tested since the
1800s.
oRandomisation, blind protocol and probability calculations are used
in the studies.
oPsychologists find if effects emerge by using a meta analysis of many
studies.
3. KEY WORDS
oESP – Extra-sensory perception. The ability to collect information
directly without using recognise human senses or with no other
logical reasoning.
oPK – Psychokinesis. The ability to move or deform inanimate objects
through mental processes alone.
oRandomisation – Material in each condition in an experiment is
presented in a random order. This helps prevent order effects.
oBlind protocol – Participants don’t know which group they are
randomly assigned to.
4. ESP ZENER CARDS
These experiments use shuffled decks of ESP cards with 5 sets of 5
different symbols on them (a cross, a circle, a wavy line, a square and
a star). These were as emotionally neutral as possible to eliminate
response bias.
Observer and subject sat opposite each other at a table with a dozen
packs laid out with a record book. The subject is allowed to shuffle
one of the packs, then this pack is cut by the observer. The subject
would remove the top card face down, call it and lay the card face
down on the table. Observer would record the call. After 5 or 25 calls
the observer would check the cards off against the calls in the record
book.
A critical reader will find faults in the experiments. There was a
chance of a sensory leakage if the subject is able to see or touch the
back or sides of the cards. There is nothing to prevent the subjects
from making small markings on the cards with his fingernails in order
to identify the cards later on. There is also no effort to guard against
recording errors.
5. METHODOLOGICAL ISSUES: FROM
THE EXPERIMENTER;
o Experimenter effect – Subtle cues or signals from an experimenter
that might affect the performance or response of subjects in the
experiments. Cues may be unconscious non-verbal cues such as
gestures or muscle tension. They may be vocal cues, such as tone of
voice.
oWoolffitt 2007 – sceptical researchers were much less encouraging than those who
believed in psi. interviewers who believed got longer responses from participants,
which led to more positive results
oPoor control – lack of control of variables will seriously compromise
the internal validity. This may lead to confounding variables ruining
the experiment, wasting time and resources.
oHansel (1989) – 13 of the reported studies that had positive results did not have
adequate controls in place. Many negative studies did apply good controls. This
suggests that the reason for positive findings would be poor methodology
6. METHODOLOGICAL ISSUES:
PARAPSYCHOLOGY
o Sheep vs Goat effect – Refers to the fact that believers in psi tend to
do better than chance expectation in psi experiments, while those
who don’t believe in psi or tend to score below chance expectation in
psi experiments.
oGertrud Schmeidler – Asked her students whether they believed in psi
before giving them ESP card tests. She called believers ‘sheep’ and
non-believers ‘goats’. Sheep scored above chance at a statistically
significant level, and goats scored below chance at the statistically
significant level. Had no idea why non-believers would score
significantly below chance time and time again. This is known as psi-
Missing. Understood how believers scored above chance expectation.
As they believe in it they want to do their best so they may look for
cues, sensory leakage, counting cards, and cheat etc.
7. HONORTON (1982)
Meta-analysis of 42 ganzfeld studies, 55% produced positive results,
with a hit rate of 38% (25% expected by chance)
8. HYMAN (1985)
Meta-analysis on same data. Also found a hit rate of 38% but 31% of
the studies showed positive results
Hyman claimed the procedures weren’t rigorous enough or were not
statistically analysed correctly. They stated flaws in randomisation of
targets and judging procedure and insufficient documentation
9. METHODOLOGICAL ISSUES: FILE
DRAWER EFFECT
The file drawer effect is when experimenters or reporters dump
negative results and don’t report them.
Mousseuu (2003)
Conducted an analysis of parapsychology journals and mainstream scientific
journals, looking for studies that reported no effect. They found many more negative
studies in parapsychology than other sciences suggesting that in parapsychology the
file drawer effect is less of an issue.
