report which we publish below is based on the 1979 report deposited
in typescript in the Society’s library where it was
available to interested persons on request. The author has now
decided that it would be fairer to all concerned if this report were
now brought into the public domain. Accordingly we are now
publishing it in a slightly emended form and have invited those who
consider themselves to be explicitly criticized therein to write a
1979 I visited the laboratory of Dr. Carl Sargent at the University
of Cambridge to observe highly successful ganzfeld psi experiments
then in progress. I observed 13 sessions, of which six were direct
hits. I considered whether the results might be accounted for by
sensory leakage, experimental error, cheating or psi. I made
observations of the sessions to test these hypotheses. The
experimental design effectively ruled out sensory leakage. However,
I observed several errors in the way the protocol was observed. Most
of these occurred in the cumbersome randomisation procedure. It was
not clear how these errors came about. Their origin might have been
clarified by either (a) a statement from Sargent or his colleagues,
or (b) by reanalyses of the raw data. However neither has been made
available. Sargent's nine ganzfeld studies form a considerable
proportion of the total ganzfeld database. In view of Sargent's
unwillingness to explain the errors found, or to make his data
available to other researchers, I suggest that these results should
be viewed with caution.
November 1979 I went to visit Carl Sargent's laboratory at the
University of Cambridge. He had carried out numerous ganzfeld
experiments with highly successful results (Sargent
1980). Meanwhile I had been unsuccessful in superficially similar
ganzfeld experiments at the University of Surrey (Blackmore 1980).
objective of the visit was to observe the methods and conditions
used at Cambridge and compare them with those used at Surrey, to see
whether any reason for the discrepancy in the results could be
determined. Because of the possibility of a psi-mediated
experimenter effect, Sargent and I hoped to carry out experiments in
which we would both act as experimenter while using the same
subjects and procedure. Sargent kindly invited me to visit his
laboratory for a month. The Society for Psychical Research (SPR)
provided a grant to cover my expenses while there. In the event I
was only able to stay eight days from November 22-30 1979.
the visit I observed several errors in the way that the protocol was
observed and the randomisation procedure carried out. The source of
these errors was unknown. After the visit I wrote a report for the
SPR (a condition of the grant) which was placed in the Society's
office and was available to any member who wished to see it.
account which follows is based on four sources of information. 1. My
original report for the SPR (which is still available from them). 2.
My notes which I made during the visit to Cambridge. 3. My private
diaries written each day. 4. Letters between myself, Sargent and
other interested parties.
the time of my visit three ganzfeld experiments were in progress. I
observed a total of 13 sessions. I either watched the experimenter
and subject, or the agent, or acted as one of these myself. The
experimenters were Sargent, Trevor Harley and student experimenters
(G. M., J. L. and K. R.). The subjects and agents were all of these,
plus other students and friends of the experimenters.
experiments used the same procedure, outlined below, with the
following variations. In one experiment subjects could remain in
ganzfeld for as long as they wished. In another, sessions lasted
either 15 or 30 minutes, and the third involved a study of
subject-agent pairs. There was also one session conducted at a
private house for the benefit of the BBC and for this the procedure
was, necessarily, slightly different. With these variations, the
procedure was as follows.
subject arrived at the experimental room where Sargent or the
student experimenter gave them coffee, chatted with them and, if the
subject was a novice, explained the purpose of the experiment and
the procedure. There was often music playing and the atmosphere was
very informal and relaxed. In some cases the subject brought a
friend to be agent, but in most cases an experimenter acted as
the subject was ready the experimenter gave him or her a pre-session
questionnaire to complete. The subject then lay on a comfortable
mattress on the floor and was prepared for the ganzfeld. Half
ping-pong balls were fixed over the eyes with sellotape and cotton
wool and white noise was played through headphones, adjusted to be
comfortably loud. A red light was shone on the ping-pong balls. The
subject was then left alone and the door shut. The experimenter's
and agent's watches were synchronised from the start of the ganzfeld
experimenter then retired to the control room from which he could
watch the subject throughout the session through a one-way mirror. A
microphone near the subject's head picked up everything that was
said. This was relayed to the control room and was both recorded on
tape and written down by the experimenter.
the agent alone (if one of the experimenters was to be agent) or the
agent with an agent's experimenter, went along the corridor into
Sargent's office to select the target for that session. There were
27 sets of pictures, each containing four black and white or
coloured pictures, chosen by Sargent and Harley to be as different
as possible from each other. One of these was selected by using
random number tables. There were two copies of each set. One
contained the four pictures in individual sealed large envelopes,
for the agent. The other, duplicate set, had all four pictures in
one envelope and this was left in the office.
each set the pictures were lettered A to D.
a small sealed envelope containing a letter A-D was selected and
used to determine which of the four pictures in that set was to be
target. The randomisation procedure is outlined in more detail
agent took the four large envelopes and the small envelope (all
still sealed) to a different building and into a soundproof booth.
At a pre-arranged time (depending on the experiment) the small
envelope was opened. This contained a letter A-D. The corresponding
large envelope was then opened and the agent took out the picture
and looked at it for the prescribed length of time making notes on a
sheet provided. He or she retained the small envelope with its
other three large envelopes remained sealed. Afterwards he or she
waited near a telephone in another room on that floor of the
the end of the ganzfeld session the experimenter went into the
subject's room, turned off the white noise, removed the headphones
and ping-pong balls and gave the subject a post-session
questionnaire to complete. He then went into the office and
collected the duplicate set of pictures, left there by the agent He
laid them out in order in front of the subject and then went through
the transcript of everything the subject had said. Each
picture was marked by the experimenter and subject together,
on a scale of 0 to 2 for correspondence with each item of the
various experimenters differed somewhat in their approach to the
judging and in the extent to which they encouraged or guided the
subject, but in all cases the total score for each picture was added
up and the subject then asked to rank and rate (on a scale of 1-100)
all four pictures.
the ranks and ratings were recorded the experimenter telephoned the
agent and asked him to come over. He always used the same words when
ringing. When the agent (and agent's experimenter when applicable)
arrived they disclosed which picture was target and showed this,
together with the other unopened envelopes, and the letter A-D, to
the experimenter and subject. The rank allocated to the target was
then known and a z-score based on the ratings was calculated.
randomisation procedure is briefly described in Ashton, Dear Harley
& Sargent 1981 and Sargent 1980. It was rather complex and I
shall therefore describe it in more detail.
were 27 sets of four pictures, numbered 1-12 and 14-28. First the
agent selected one of these by taking an arbitrary starting point
into the RAND random number tables, and taking the first number
between 01 and 28 (excluding 13). This determined which set was to
pictures in each set were lettered A-D. Which was to be target was
determined as follows. There was a pile of 20 small brown sealed
envelopes constantly on the desk in the office. Each contained two
pieces of white card enclosing a slip of paper bearing one of the
letters A, B, C or D. There were five of each letter in the pile,
the envelopes being all of the same type and unmarked. The agent (or
agent's experimenter) opened the book of random digits arbitrarily
selected an entry point and took the first number between 01 and 20.
He counted this number of envelopes down the pile and cut it. He
then took the next number in the list, and counted down the pile
again, taking the envelope
indicated. Once in the soundproof room he opened his envelope and
used the letter it contained to determine which of the large
envelopes would be opened.
the pile obviously contained only 19 envelopes. To restore it to 20
the one used had to be replaced; and by one of the same letter. In
four drawers adjacent to the desk, spare envelopes were kept: A's in
the top drawer, down to D's in the bottom drawer. Like those in the
original pile they were, of course, of the same type and unmarked.
Their contents were only known by which drawer they came from. After
each session the experimenter looked up which letter had been used
for that session, took an envelope from the corresponding drawer and
placed it in the main pile. In this way the main pile could retain
its contents unchanged.
my visit I observed 13 sessions. Of the 12 conducted at the
laboratory, six were direct hits. This is a hit rate of 50 per cent
when 25 per cent is expected by chance. Obviously the number of
sessions was small but the results seemed to confirm Sargent's
previous high rate of scoring.
PHASE 1. DAYS 1-3
the first three days of my visit I observed five sessions (not
counting the BBC session). During these sessions I did not take part
but just watched either the experimenter or the agent. I took
detailed notes, intending to compare the procedure with my own. Of
the five sessions, three produced a rank 1 or direct hit, one a rank
2 and one a rank 4. That is a hit rate of 60 per cent when 25 per
cent is expected by chance (p = -12). These results seemed quite
unlike my own chance results.
whole purpose of the visit was to try to determine the reason for
the difference in results between my experiments and those of
Sargent. I considered the following five hypotheses and made
Differences in 'atmosphere'
setting and procedure appeared to be potentially far more
psi-conducive than mine. The room was much larger and more pleasant.
There was music and coffee and the whole environment was much less
like that of a laboratory.
Differences in experimenter
was quite clear that the main experimenter was extremely confident
about the expected results and conveyed this confidence to the
subjects The experimenter's role during the judging was also
much more active with the experimenters, especially Sargent, often
encouraging the subject making suggestions and pointing out
correspondences. This would allow for more influence by the
experimenter, which might be good or bad. With a skilled
experimenter, it might maximise the use of the available
design seemed to exclude very efficiently the possibility of sensory
leakage. Duplicate target sets were used so that no handling cues
were available the subject and subject's experimenter were entirely
isolated from the agent from the time the watches were set until the
phone call was made By this time the subject had made his choice. In
the sessions I observed I could see no means of sensory leakage
unless protocol were violated. I observed no such violations of
protocol at this stage.
questions arise here. First does the procedure allow for errors to
take place? Second are those errors likely to be important to the
results, and third did any errors actually occur?
sort of accidental errors which might occur include incorrect
replacement of pictures in envelopes, errors in the timing, in
giving the right questionnaires in the addition of marks or the
calculation of z-scores.
the complex randomization procedure seemed to allow for errors to
take place reasonably easily. For example, if an envelope were
incorrectly replaced in the pile this would lead to a bias in the
pile which might never be detected. Second, however, such a bias
would produce only a small effect on the overall scores.
only one error was observed during this stage. On one occasion, when
the duplicate set of pictures was brought in for judging, it was
found to contain only three pictures instead of four. The problem
was efficiently resolved. J L (a student) rang the agent (G. M.) (in
my presence) and asked him to see whether he had an extra picture by
mistake and if so, to place it on the ground floor of the other
building and then return to his place by the phone. Sargent then
went to fetch it and the judging proceeded as usual. This sort of
error can easily arise in experiments of this complexity but, if
handled correctly like this, could not produce spurious results. No
other errors were observed at this stage.
had no reason to suppose that anyone might be cheating. However,
parapsychology is still a controversial subject and it is
conventional to consider whether a protocol is proof against obvious
methods of cheating, even though completely cheat-proof designs are
not to be expected and are probably unattainable. My intention was
to look for any obvious methods and to ensure that they were not
taking place. In this way I could be reasonably certain that the
only remaining hypothesis was that of ESP.
the visit I had thought of several possible methods. These involved
the experimenter finding out which picture was target, and pushing
the subject towards it, or the agent opening a different picture
from the one specified by the randomization. I could now see that
the experimental design made any of these methods extremely
difficult. However, the complex randomization procedure seemed to
allow for several methods of cheating. The observations necessary to
check up on these were simple and unobtrusive and I believed them to
be necessary if I was to convince myself and others of the validity
of the results. This led to the second phase of the observations
during which I checked various new hypotheses.
PHASE 2. DAYS 4—5
these two days I observed a further five sessions. I was subject in
one of them. There were three direct hits, one rank 2 and one rank
3. This is a hit rate of 60 per cent, where 25 per cent is expected
by chance. For these few sessions alone, the results are almost
significant (p = -055). For the ten sessions observed so far the sum
of ranks was 17 (p = -016).
chance was very unlikely to account for these results. Sensory
leakage or simple experimental error had been excluded and so the
remaining possibilities seemed to be either ESP or cheating. I
should point out that it was probably clear to everyone in the lab
that I was sceptical about the possibility of ESP. I believe that
having a sceptical observer there was not particularly pleasant, but
on the other hand the sessions proceeded in a relaxed and pleasant
atmosphere and the results were not adversely affected by my
presence. I did not tell anyone about the specific hypotheses I had
in mind. I hoped only to make some simple observations which would
exclude them to my own satisfaction.
this in mind I considered whether any simple methods of cheating
were possible within this experimental design. I considered the
following hypothetical methods and ways of detecting them.
The pile of small envelopes could be biased. The experimenter would
then know which picture would be target and could 'push' the subject
towards that one. This would result in an overall bias in the
targets used, unless the pile were regularly replaced. This
would mean having extra piles of envelopes hidden somewhere.
The agent could guess which picture the subject would choose. This
would be especially easy if he knew the subject well, or the subject
had taken part in previous trials. He could then cause this picture
to be selected by several methods e.g.
a. By marking the main pile of twenty envelopes and selecting the
b. By taking an envelope from a drawer instead of from
the main pile.
c. By concealing extra envelopes to use for the
purpose (I thought of this some days later).
methods would all be detectable. If (b) occurred a small envelope
would disappear from the drawer during the trial instead of
afterwards (during replacement). The pile might also remain at 20,
instead of 19, during the trial. Or if it were reduced to 19, two
envelopes would be used during one trial instead of one. Also the
pile would become biased because the one removed would not match the
one later replaced.
A most effective method would be for one person to arrange both to
carry out a false randomization (as in 2) and also be present at the
judging to 'help' the subject.
these methods involve violations of protocol. Some would be easily
detectable and I therefore decided to make certain simple
observations which in no way interfered with the running of the
experiment or with anyone's privacy. If I found no indications that
any of them were happening, then I could be reasonably confident
that the results were due to ESP.
effects predicted were as follows:
The main pile might be marked.
The main pile might be replaced-or partly replaced.
The main pile might be biased (this could arise from several
only way to check this would be to open the envelopes which I did
not wish to do (but see later).
There might be piles of extra envelopes around the room. I thought
it improper to search for them and did not wish to do so.
Envelopes might disappear from the replacement drawers during,
rather than after, a session.
Two envelopes, instead of only one, might disappear from the drawers
for one session.
check on these last two possibilities I decided to count the numbers
of envelopes in each drawer both during each session and afterwards,
and to watch the replacement procedure whenever possible.
recap—my hypothesis was that if cheating were taking place I would
expect envelopes to disappear from the drawers during, rather than
after, a session, or for more than one envelope to be used for each
main pile did not seem to be marked and was not switched during
these two days. I counted the envelopes in the drawers from session
8 onwards. The results are shown in Table 2.
this table it can be seen that between sessions 8 and 9 two
envelopes, not one, disappeared from the drawers. One was a 'D'
(which is correct to replace the 'D' which was target for session
8). The other was a 'B'. This was target for session 9, but of
course the 'B' for that session should have come from the main pile;
only being replaced later by one from the drawer.
later observed the replacement procedure and this was carried out
correctly. i.e. another 'B' was taken from the drawer and placed in
the main pile.
the 'B' for trial 9 had come from the drawers instead of from the
main pile (as hypothesised in 2b above) this would probably result
in there being an extra 'B', instead of some other letter, in the
main pile. I was unable to check on this at this time.
noted certain other problems all concerning the same trial. During
this trial (No. 9) I stayed with the experimenter (K. R.) and
watched the judging. Sargent was not officially taking part, but he
came in during the judging. He said he wanted to help, because it
was a particularly difficult session, the subject having said only a
few words. He seemed to push the subject towards picture B. I wrote
this observation in my notes at the time and K. R. independently
mentioned it tome as well. Note that I wrote down this observation
before I counted the envelopes in the drawer. Of course this ought
not to matter because Sargent should not have had any way of knowing
the identity of the target (but see later).
the same trial there was also an arithmetical error: it was later
discovered that the experimenter had added up the marks wrongly.
Picture B had not been given the most marks and so this session
should not have been a direct hit. When he discovered this Sargent
checked the addition for all previous trials and found nothing else
wrong. Rejudging would be one way to clarify whether there really
was a good correspondence between the subject's mentation and the
picture B. Sargent said that he intended to do this rejudging.
PHASE 3 DAYS 6-7
intended to continue observing. I also considered asking Sargent
whether we could open the envelopes in the main pile to see whether
it had become biased as hypothesised. However, Sargent became ill
with 'flu' and was away on Day 6. I was therefore unable to observe
any more sessions or to ask him about the main pile.
Sargent's absence I discussed the experimental design and its
potential problems with Trevor Harley. I told him that I was worried
that the main pile of 20 envelopes might become biased, and no-one
would know it had happened.
assured me that Sargent always did the replacement himself and that
he would not make such errors. Nevertheless, he thought it was a
good idea to open them to find out. He checked that there were new
envelopes of the same kind available. I then opened all the
envelopes. There were 19, the replacement for the previous trial not
yet having been done. There should have been 4 'A's, 5 'B's, 5 'C's
and 5 'D's. There were in fact 5 'A's, 6 'B's, 4 'C's and 4 'D's. As
I had predicted there was an excess of 'B's.
and I discussed the possible ways this error could have come about.
Accidental errors made originally in the drawers.
Accidental errors made in replacement to the main pile. Two such
errors could create the bias observed.
As a by-product of the methods (of cheating) outlined above.
then opened the envelopes in the drawers. Drawers B-D were correct
but the 'A' drawer contained 2 'D's in addition to several 'A's.
Harley and I replaced all the letters in new envelopes and
reconstituted the main pile correctly.
of finding these errors I discussed with Harley the reasons I had
for worrying about them. I explained about the missing 'B' on
session 9, and the other observations made concerning that session.
Harley immediately recalled that on that session there had been a
change from the official procedure.
was to be agent. It was an experiment in which there was little time
for the agent to do the randomization. Harley therefore asked
Sargent to prepare things for him; apparently meaning him to get all
the envelopes, tables and so on ready. In fact Sargent actually
carried out the randomization and handed Harley the set of pictures
and the small envelope. Harley took them and used them for that
session. This should not have mattered since officially Sargent was
to have no further role in that session. However, of course, we now
knew that Sargent had come into the judging session on that occasion
and had apparently 'pushed' the subject towards the correct picture.
following day Sargent was still away ill. Harley and I wished to
check up on some details of previous sessions and therefore looked
for the book in which they were recorded. We could not find it, but
in the process Harley found a sealed envelope, like those used in
the randomization, under some papers. We decided to look for any
further ones. We found a single one in a drawer and a pile of three
under some papers. We opened them all. The single ones were a 'C'
and a 'D'. The pile of three were all 'A's. We found no 'B's.
discussed possible reasons for them being there. One possibility
appeared to be the method 2c, outlined above. If there were no 'B's
concealed, then only method 2b could be used and would result in a
'B' going missing from the drawers, as observed on trial 9. We
discussed alternative explanations.
said that the envelopes for this series of experiments had been
specially prepared all at once and placed either in the main pile or
the drawers. Envelopes of that size and colour had not been used in
any previous experiment. He could think of no reasons for there
being any extra ones around the room.
further sessions were conducted, by student experimenters, in
Sargent's absence. These obtained ranks 3 and 4; both misses.
Sargent returned after his illness Harley presented him with the
findings so far. These were:
The bias in the main pile and errors in the drawers.
The extra envelopes found around the room.
The series of events surrounding session 9.
denied that any of these errors had come about deliberately and
supplied alternative explanations for them. I hoped that Sargent
would write his own account and provide these explanations himself.
Since he has never done so I shall try to be fair to what he told
me. We now have two alternative hypotheses to account for the
I had predicted that certain methods of cheating would lead to a
bias in the main pile. I found that bias.
said that the errors in the pile must have come about by accidental
errors in replacement.
calculated the maximum size of any spurious effect that could be
created by this bias and found it to be only 3 per cent; a
negligible effect when the average hit rate was about 45 per cent.
Clearly if the bias were accidental it could not account for the
successful results. On the other hand if it came about as a
by-product of those methods of cheating, a very large effect size
could be obtained.
this time the error in addition (mentioned above) was also found.
Neither Sargent nor I had any explanation for the 'D's in the 'A'
I had predicted that certain methods of cheating would necessitate
having extra piles of envelopes hidden around the room. These were
explained that the extra envelopes had been left over from a
previous experiment, although Harley had previously said that this
was very unlikely.
It now appeared that on one session—number 9—the following
events had taken place.
Sargent did the randomization when he should not have.
A 'B' went missing from the drawer during the session, instead of
Sargent came into the judging and 'pushed' the subject towards 'B'.
An error of addition was made in favour of 'B' and 'B' was chosen.
'B' was the target and the session a direct hit.
said he had done the randomization because Harley asked him to.
Sargent said he had removed a 'B' because it was bent and therefore
distinguishable from others. He said he had already told Harley
about this. Harley now said he remembered being told although he had
not remembered this previously when he and I discussed the problem.
said there was no harm in him coming into the judging since he did
not know the identity of the target, even though he had done the
randomization. He denied 'pushing' the subject.
are therefore two hypotheses to consider. The hypothesis of cheating
led to the discovery of the errors. It explains them fairly neatly
and could, if extrapolated to the whole experiment, account for the
large effects observed'.
alternative is ad hoc, and cannot account for the large
effects (these would have to be attributed to psi). It would imply a
good deal of carelessness in the running of the experiment.
considered that the evidence was not conclusive in favour of either
hypothesis and that more evidence was needed. I did not wish to make
any accusation, or even implication, of cheating, without conclusive
evidence that it had occurred. It therefore seemed essential to gain
further information which might support one or other hypothesis, and
in the meantime not to publicise the findings.
were several kinds of information which would be relevant:
Further observations of the experiments in progress. These were
planned for a second visit of three weeks early in 1980. However,
two weeks after I left Cambridge, Sargent informed me that he did
not wish me to return, which of course I accepted.
The results of further experiments using the same procedure and
subjects, but a different experimenter. This was also part of our
original plan, but did not take place for the same reason.
A full report by Sargent (and his colleagues) of their explanation
of the errors.
January 1980, I wrote a report for the SPR archives. This was to be
available to SPR members on request, but I hoped it would soon be
made redundant by a published version. Sargent and I agreed that we
would each write our own version of the events. I wrote mine and
sent it to him. He wrote an early (confidential) version, but never
produced a final one. He continued to promise he would and therefore
I waited and did not publish my own account.
it became clear that Sargent was unlikely to produce a report, I
discussed with Harley the possibility of publishing a joint account.
We differed in some respects but agreed that we could write a report
together if the points of disagreement were made clear. Harley did
not write a report. I finally concluded that no written explanation
was likely to be forthcoming from either Sargent or Harley.
Further analyses of raw data from previous experiments.
were several ways in which the raw data might help to test the
hypotheses. For example, according to some methods of cheating one
would expect the most popular picture in any set to have been target
more often than predicted by chance. I asked whether I could check
this. However Harley said that the pictures in each set were changed
from time to time, without any record being kept, and that it would
be impossible to check this from the existing records.
hypothesis was that, if one person were cheating and pushing the
subject towards the target, rejudging should give poorer results
than the original ones. This would be easy enough to do and Sargent
said that he intended to do it. However he never published the
results of any rejudging.
if one person were cheating, the most significant results should
occur when they were acting as agent or experimenter, though of
course this could also occur because of a psi-mediated experimenter
effect. In fact there is evidence that scores were higher when
Sargent took part in the few sessions observed during this visit and
in published data (Ashton, Dear, Harley and Sargent 1981).
hoped to be able to check the entire data base for this effect. This
would mean having the Blue data book in which the names of all
participants are recorded.
another suggestion was made by Parker and Wiklund (1982). Cheating
could take place by manipulation of the randomisation combined with
knowledge of the subject's likely responses (as in 2a-c above). The
easiest way to find this out is by looking at the subjects' responses
on previous trials. Wiklund and Parker suggested that in those trials
where Sargent was responsible for the randomisation, and the subjects
did not make direct hits, there would be above chance scoring if the
target were matched with the subject's mentation on a previous trial
(Parker and Wiklund). This could be checked from the raw data and they
therefore asked Sargent for those data.
suggestions provide definite ways in which the implications of
cheating could be lifted. If Sargent supplied the raw data other
researchers could check them for these effects. If these effects were
found, that hypothesis would be strengthened. If they were not found
then the cheating hypothesis would lose much of its force.
kept hoping that this would happen and the truth become clearer.
However Sargent refused to make his data available. Several informal
requests for the data were made. Then when these failed to elicit any
data, official requests were made through the Parapsychological
Association. Sargent still did not supply the data, nor any reason for
1984 the PA Council asked Martin Johnson to head a committee to
investigate the case. The final report of this committee is now
available. Council reprimanded Sargent for failing to respond to their
request for information within a reasonable time.
view of this lack of cooperation it is not possible to test any of
these hypotheses against the data. Also there now seems little hope of
obtaining any new evidence and therefore we must assess the case on
the basis of what evidence we already have.
have been criticised for not publishing a full account earlier. I hope
I have now made clear my reasons. I did not wish to publish something
which discussed the hypothesis of cheating, (a) while there were still
promises that others would supply alternative explanations for my
findings and (b) while there was still some hope that further evidence
would come to light.
think there is still doubt as to the correct hypothesis. However, any
hope that this will be speedily resolved now seems to be unrealistic.
I am therefore presenting the evidence I have, as accurately as
possible. I hope that others will add their versions to mine.
has recently been considerable controversy concerning the value of the
ganzfeld database in providing evidence for psi. The many experiments
involving Sargent as experimenter form a very substantial and
important proportion of that database. According to Hyman (1985)
Sargent's 9 studies and Honorton's 5 account for one third of the
total. According to Honorton (1985) Sargent's experiments have the
second highest effect size, after Honorton's own.
Sargent's findings were removed from this database it would be
considerably weakened as evidence for psi.
H.T., Dear, P.R., Harley, T.A. and Sargent, C.L. (1981) A four-subject
study of psi in the ganzfeld. Journal of the Society for Psychical
Research, 51, 12-21
S. J. (1980). Extrasensory Perception as a Cognitive Process.
Unpublished PhD Thesis, University of Surrey.
C. (1985). Meta-analysis of psi ganzfeld research: A response to
Hyman. Journal of Parapsychology, 49, 51-91
R. (1985). The Ganzfeld Psi Experiment: A Critical Appraisal Journal
of Parapsychology, 49 3-49
A. and Wiklund, N. (1982). The ganzfeld: A methodological evaluation
of the claims for a repeatable experiment. Unpublished.
C. L. (1980). Exploring Psi in the Ganzfeld. Parapsychological
Monographs No 17
C. L., Harley, T. A., Lane, J. and Radcliffe, K. (1981). Ganzfeld psi
optimization in relation to session duration. Research in
Parapsychology 1980, 82-84.
C. L. and Matthews, G. (1982). Ganzfeld GESP performance in variable
duration testing. Journal of Parapsychology 1981, 159-160
wish to thank Dr. Carl Sargent for inviting me to visit his laboratory,
and the Society for Psychical Research for financial support.
See also the following responses published
in the same journal issue.
Harley,T. and Matthews,G. (1987) Cheating,
psi, and the appliance of science: A reply to Blackmore. Journal of
the Society for Psychical Research, 54, 199-207
Sargent,C. (1987). Sceptical fairytales
from Bristol. Journal of the Society for Psychical Research, 54,
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