section briefly details our methodology, for a full discussion
download a sample
investigation report. Investigations are compared to conventional
The section explains more about what PSI
does on investigations, and more importantly why we do what we do.
Italicised words carry definitions to their right. PSI methodology is split into three sections,
which are outlined below.
Ethical issues associated with
investigations are also considered.
PSI conducts investigations in the context
of three research objectives:
1. To develop a case study of a particular property
2. To conduct qualitative, naturalistic research over the course of the
3. To perform quantitative field research
Investigations as a case study
Investigations as naturalistic research
Reliability: Human testimony
Reliability: Human psychology
Reliability: Recording equipment
Quantitative field research
Field Experiments (opens in separate window)
Investigations as a case
One research objective of conducting a paranormal investigation is to
build up an overall picture of a property. The purpose of this objective
is to build a catalogue of allegedly ‘haunted properties’ and provide a
rich and detailed report for the benefit of owners of the properties.
As such, the report brings together several strands of research:
■ A historical report of the venue
■ A catalogue of anomalous phenomena reported over time
■ Witness reports of ‘anomalous phenomena’ derived from interviews with
■ An account of any phenomena recorded over the course of the
■ An account of any information established through non-scientific
spiritual methods over the course of the investigation.
Case studies are not randomly selected and are either self-selective, by
venue owners approaching PSI or venues are purposefully chosen because
of accounts of anomalous phenomena.
Case study reports do not impose limitations or constraint by requiring
all phenomena to be operationally defined. There is no attempt to
manipulate variables and no attempt to systematically determine how
No analysis or critical assessments are made of case studies, and no
conclusions are drawn from them as to whether reported phenomena are
valid or accurate, and are not used to generalise findings.
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Investigation settings are slightly artificial in nature. Operationally
an investigation consists of a group of trained participants being used
to self-report, in non-operational terms, any phenomena witnessed.
Individuals act as participants as they are split into groups, spending
forty-five minute sessions in different locations, being asked to report
what is experienced into voice recording equipment. Such accounts are
Attempts are made to record by various means any phenomena reported for
reasons of verifiability (see below). In addition, attempts are made to
record phenomena independently of participants, following the tenacious
theories that phenomena can include unexplained voices when white noise
is recorded, and that phenomena can include spontaneous PK. Thus sound
recorders are set up to record against static radio or television
channels, and camcorders record ‘trigger’ objects to test the PK
Further tenacious paranormal theories are occasionally tested during
investigations. Methodologies for these are noted in the relevant
Participants also act as ‘investigators’ by engaging in quantitative
field research, which will be described later.
Such naturalistic research presents a large number of threats to
reliability and validity. Attempts are made to minimalise such threats,
but it is not possible to eliminate all threats:
Reliability: Human testimony
Human participants’ testimony is flawed, representing a problem of
■ Participants thus carry photographic equipment to attempt to capture
phenomena witnessed. However, photographic equipment can also be flawed,
as discussed later.
■ Self-reports are made instantly, as opposed to reliance on
retrospective reporting, a method associated with even more problems of
Reliability: Human psychology
Empirical phenomena reported by participants can be psychologically caused,
presenting further problems of reliability:
■ Participants are open to ‘suggestion’. Efforts are made to minimise
the level of suggestion. For example groups of participants are not
permitted to discuss with other groups anything witnessed during
sessions, to avoid the experiences of one group affecting the reporting
of another group. It is more difficult, however, to limit the level of
suggestion within a group, as participants can be influenced by what
others are experiencing. These problems cause treating witness reports
as ‘reliable’ to be flawed, making analysis difficult.
■ Participants can be primed by expectation. Participants are not
permitted to research the history of venues in advance of
investigations, so as not to be influenced by the knowledge of past
events, owners or previous phenomena reported. Similarly, in the
selection of venues, efforts are made to avoid venues previously
‘studied’ by television programs focusing on the paranormal. Any
evidence reported by investigation leaders who have researched or dealt
with venue owners in advance of the investigation is treated as suspect
during analysis. Finally, participants are deemed to be ‘primed’ by
having participated in paranormal investigations before.
■ Empirical reports can be the result of hallucination, including
group hallucination and imagination. It is noted when phenomena are
witnessed by more than one participant, in the attempt to promote
inter-observer reliability, but the problem of group
Efforts are made to control conventional factors that could cause
affected perception, such as a prohibition of use of alcohol or
mind-altering drugs on the day of investigations. Similarly, any
evidence reported after, say, 0200 can be viewed as especially unreliable, due
to the potential of cause by sleep deprivation. The problem of witnesses
reporting events that may have not taken place is possibly the greatest
problem of reliability, calling all evidence into question that was not
verified by photographic equipment.
■ Sampling errors can effect phenomena recorded. The individuals own
experiences and mindset can affect what is reported. For example studies
have shown that those who self define as ‘sceptics’ have less ability to
report phenomena when it is witnessed, whereas those who self-define as
‘believers’ have been shown to report phenomena where none is in
Reliability: Recording equipment
Reliability of photographic equipment is a threat to verification of
recorded empirical phenomena. For example digital cameras may appear to
record anomalies where it is in fact distorting light, dust, moisture or
reflections. Where possible these variables should be controlled, but
otherwise analysts should have an awareness of the location and any
potential factors which could interfere with photographic equipment.
Further, use of digital cameras are backed up with use of 35mm cameras
and camcorders, which are held to be more reliable. Finally, all
locations that are to be the settings of sessions are photographed on
two occasions before the investigation to act as a baseline.
Problems of internal validity can be identified and attempts made at
control. In a natural largely uncontrolled environment there can be
problems associated with outside events, which can be confused by
participants as anomalous phenomena. All possible outside events must be
recorded and verified with other groups or by venue owners before any
inferences are drawn. For example all potential phenomena recorded are
noted with the time of the event, and all teams have synchronised time
pieces. This allows events reported outside of the session setting to be
verified by other groups. Venue owners are also interviewed between
sessions concerning any possible outside events. Similarly, analysts
should have an appreciable knowledge of the venue, to be able to analyse any structural factors. However, it is not possible to eliminate all
outside events, so even corroborated reports must be treated
■ One identifiable threat to construct validity is bias,
including demand characteristics, social desirability and experimenter
bias. Again, it is nearly impossible to guarantee elimination of all
such biases. Trained, experienced participants who are not reinforced
for reporting phenomena help to overcome these biases, but it is
difficult to fully rule them out.
■ A further threat to construct validity is that alternative theories
can be found to explain phenomena. Any explanation found should be
deemed to be the most ‘likely’ explanation. Therefore at the stage of
analysis, evidence should be ruled out if there is a more likely
explanation for a reported phenomena, other than it being ‘unexplained’.
An arguable strength of paranormal investigations is the relative
ecological validity of the research. That is investigations are
conducted in ‘natural settings’, in properties actually reputed
to associated with anomalous phenomena. There are, however, significant
threats to the ecological validity of investigations and to the nature
of ‘naturalistic’ research specifically. Investigations are
forced environments with use of monitoring equipment. Efforts are made
to minimalise the intrusiveness of such operations, but ‘investigations’
can never fully represent ecologically valid natural conditions.
Following naturalistic research ‘investigations’ all evidence is
analysed against the weaknesses in reliability and validity as outlined
Analysis tends to be a process of elimination of all evidence, and the
occasional drawing of tentative conclusions that recorded phenomena may
be, as yet, unexplained.
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Quantitative field research
Such research contends to test the tenacious paranormal theory that
there is a correlational – not in this case causal – relationship
between phenomena reported by participants and and fluctuations in the
environment recorded using equipment.
Tenacious theories expound that there is a correlation between phenomena
and fluctuations in: temperature, air pressure, humidity, presence of
ionic particles and in the electromagnetic field.
Thus baseline readings are recorded on two occasions in advance of the
investigation, once immediately before. Participants record readings
every twenty minutes throughout sessions to establish a baseline
against which readings recorded when phenomena are reported can be
There are numerous problems of reliability and validity associated with
such correlational research:
Reliability and validity
■ Human error can compromise the reliability of equipment readings.
Whilst participants are well trained in the use of equipment and are
supervised at all times, human error cannot be discounted.
■ Equipment error can further compromise reliability. All equipment is
duplicated and readings compared with each other before investigations
begin, but equipment error can never be fully ruled out.
■ Problems of internal and construct validity can compromise equipment
readings. That is, outside a laboratory setting it is difficult to
establish a direct link between equipment readings and reported
phenomena: extraneous factors can account for fluctuations. Thus,
investigation leaders must attempt to control or at least have knowledge
of the causes of such extraneous factors, so elimination can take place.
For example natural or artificial temperature fluctuations should be
controlled or established. Further, external factors that cause
electromagnetic field fluctuations should be controlled (for example turning off electrical
equipment and mobile phones) or established (for example establishing
the location of power lines).
During the stage of analysis, correlation between reported phenomena and
environmental fluctuations can be highlighted. However there is need to
establish if the frequency or intensity of the fluctuations constitutes a
significant correlation, that could not have occurred naturally.
The frequency of such correlation can be too few within one session or
investigation to attempt to establish a correlation, and may be more
appropriate to meta-analyse across investigations.
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Analysis and conclusions
As noted previously case study findings are not suitable for either
analysis or conclusion.
Evidence recorded through naturalistic and field research should be
analysed in respect of the methodological weaknesses in reliability and
validity as outlined above.
In practice, the majority of empirically recorded phenomena are ruled
out under the tests of reliability and validity. However, occasionally
evidence withstands scrutiny and can be declared ‘unexplained’. It
should be noted that on the rare occasions that evidence is not
explainable it should not be described as paranormal and will almost
certainly not ‘prove’ the existence of the paranormal. Firstly, by
definition spontaneous anomalous phenomena tend not to be repeatable, so
proof cannot be established. Secondly, outside of a laboratory setting, it
cannot be positively established that the phenomena are not caused by
more mundane extraneous factors.
If a significant relationship between
phenomena reported and environmental fluctuations is established it should be
emphasised that this is a correlation, not a causal relationship. That is,
without the ability to manipulate the independent variable, is it not
possible to conclude that such readings are caused by the paranormal.
For example, studies have shown correlation between fluctuations in the
electromagnetic field and the reporting of phenomena, but argued that
electromagnetic fluctuations caused perception of phenomena, as opposed
to electromagnetic fluctuations being caused by phenomena that had been
Finally and conversely, it should be noted that an investigation revealing no evidence
of spontaneous anomalous phenomena does not prove that a venue is not
‘haunted’, at best it proves that there was no phenomena reported on
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Ethical conduct is of great importance when
conducting investigations, especially as human participants are involved
and individual’s properties are the setting.
A number of investigation groups operate with unethical practices. PSI
offers assurances of its strong ethical standards, and presents the
basis tenets of its ethics, below:
■ Doing no harm. This relates to not putting participants at risk
of undue physical or emotional harm during an investigation, and being
insured against liability. Participants are chosen via a rigorous
selection and training procedure that ensures they are not of a nervous
disposition. PSI carries out safety assessments in conjunction with
venues. PSI mediums offer spiritual protection for participants who
self-define as ‘believers’. PSI insists each investigator completes and
carries with them a full medical form.
■ Consent. All individuals participate with informed consent and
no individuals under the age of 18 are not permitted on PSI
■ Deception: All participants are fully briefed, trained and
aware of all research objectives.
■ Freedom to withdraw. All participants are free to withdraw at
any time. Further, venue owners have the right to halt any
investigations at any time.
■ Confidentiality. All evidence and information gathered on
investigations is held in confidence within the organisation unless
agreed otherwise, this applies to work with the press. For these
purposes the organisation is defined as constrained to trained team
members, and specialists associated with PSI to whom confidentiality is
■ Debriefing. All participants are fully debriefed and unload
experiences at the end of investigations, to ensure they leave the in
the same psychological state in which they arrived. PSI has follow up
procedures should participants need to discuss any issues after any
■ Reporting research. PSI has a duty to take due care any
reporting of results, especially to the media. PSI take the
responsibility as being seen as ‘representing’ the field very seriously.
PSI never sensationalises evidence or vies for attention. PSI never
makes unscientific claims, including concluding that a property is
‘haunted’, or not ‘haunted’.
■ Treatment of venues and owners. All
venues and owners are treated with respect at all times. PSI always
shares results with venues, abides by their wishes and continues contact
for as long as venues and owners need. Ethical responsibility extends to
not conducting investigations in any way which might cause a venue to
feel any 'presence' they feel has been exacerbated. PSI never
performs 'clearances', but can refer venue owners to suitable individuals
or groups should they request that information. PSI has special
ethical procedures for dealing with private homes and families.
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