Glossary of Parapsychological Terms


The definitions of most of the following terms have been borrowed or adapted from A Glossary of Terms Used in Parapsychology by Michael A. Thalbourne (republished by Puente Publications, Charlottesville, VA, USA, 2003).

AGENT: In a test of GESE the individual who looks at the information constituting the target and who is said to "send" or "transmit" that information to a percipient; in a test of telepathy and in cases of spontaneous ESP, the individual about whose mental states information is acquired by a percipient. The term is sometimes used to refer to the subject in a test of PK.

ANOMALOUS COGNITION (AC): A form of information transfer in which all known sensory stimuli are absent; that is, some individuals are able to gain access to information by an as yet unknown process; also known as remote viewing (RV) and clairvoyance.

ANOMALOUS PERTURBATION (AP): A form of interaction with matter in which all known physical mechanisms are absent; that is, some individuals are able to influence matter by an as yet unknown process; also known as psychokinesis (PK).

CALL: (As noun), the overt response made by the percipient in guessing the target in a test of ESP; (as verb), to make a response.

CLAIRVOYANCE: Paranormal acquisition of information about an object or contemporary physical event; in contrast to telepathy, the information is assumed to derive directly from an external physical source and not from the mind of another person.

CLOSED DECK: A procedure for generating the target order for each run, not by independent random selection of successive targets, but by randomization of a fixed set of targets (e.g., a deck of 25 ESP cards containing exactly rive of each of the standard symbols).

CONFIDENCE CALL: A response the subject feels relatively certain is correct and indicates so before it is compared with its target.

CRITICAL RATIO (CR): A mathematical quantity used to decide whether the size of the observed deviation from chance in a psi test is significantly greater than the expected degree of random fluctuation about the average; it is obtained by dividing the observed deviation by the standard deviation; also called the z statistic. Critical Ratio of Difference ([CR.sub.d]): A critical ratio used to decide whether the numbers of hits obtained under two conditions (or by two groups of subjects) differ significantly from each other; it is obtained by dividing the difference between the two total-hits scores by the standard deviation of the difference.

DECLINE EFFECT: The tendency for high scores in a test of psi to decrease, either within a run, within a session, or over a longer period of rime; may also be used in reference to the waning and disappearance of psi talent.

DIFFERENTIAL EFFECT: In an experiment where the subjects are tested under two different procedural conditions: (i) the tendency of subjects who score above chance in one condition to score below chance in the other, and vice versa; (ii) the tendency of one condition to elicit psi-hitting from the group of subjects as a whole and the other condition to elicit psi-missing.

DISPLACEMENT: A form of ESP shown by a percipient who consistently obtains information about a target that is one or more removed, sparially or temporally, from the actual target designated for that trial. Backward Displacement: Displacement in which the target extrasensorially cognized precedes the intended target by one, two, or more steps (designated as -1, -2, etc.). Forward Displacement: Displacement in which the target actually responded to occurs later than the intended target by one, two, or more steps (designated as +1, +2, etc.).

ESP CARDS: Special cards, introduced by J. B. Rhine, for use in tests of ESP; a standard pack contains 25 cards, each portraying one of rive symbols, viz., circle, cross, square, star, and waves.

EXPERIMENTER EFFECT: An experimental outcome that results, not from manipulation of the variable of interest itself, but from some aspect of the experimenter's behavior, such as unconscious communication to the subjects, or possibly even a psi-mediated effect working in accord with the experimenter's desire or motivation.

EXTRASENSORY PERCEPTION (ESP): Paranormal cognition; the acquisition of information about an external event, object, or influence (mental or physical; past, present, or future) in some way other than through any of the known sensory channels.

FORCED-CHOICE TEST: Any test of ESP in which the percipient is required to make a response that is limited to a range of possibilities known in advance.

FREE-RESPONSE TEST: Any test of ESP in which the range of possible targets is relatively unlimited and is unknown to the percipient, thus permitting a free response to whatever impressions come to mind.

GANZFELD: Term for a special type of environment (or the technique for producing it) consisting of homogeneous, unpatterned sensory stimulation; an audiovisual ganzfeld may be accomplished by placing halved ping-pong balls over each eye of the subject, with diffused light (frequently red in hue) projected onto them from an external source, together with the playing of unstructured sounds (such as "pink noise") into the ears.

GENERAL EXTRASENSORY PERCEPTION (GESP): A noncommittal technical term used to refer to instances of ESP in which the information paranormally acquired may have derived either from another person's mind (i.e., as telepathy), or from a physical event or state of affairs (i.e., as clairvoyance), or even from both sources.

GOAL-ORIENTED: Term for the hypothesis that psi accomplishes a subject's or experimenter's objective as economically as possible, irrespective of the complexity of the physical system involved.

MACRO-PK: Any psychokinetic effect that does not require statistical analysis for its demonstration; sometimes used to refer to PK that has as its target a system larger than quantum mechanical processes, including microorganisms, dice, as well as larger objects.

MAJORITY-VOTE TECHNIQUE (MV): The so-called repeated or multipleguessing technique of testing for ESP. The symbol most frequently called by a subject (or a group of subjects) for a given target is used as the "majority-vote" response to that target on the theory that such a response is more likely to be correct than one obtained from a single call.

MEAN CHANCE EXPECTATION (MCE): The average (or "mean") number of hits, or the most likely score to be expected in a test of psi on the null hypothesis that nothing apart from chance is involved in the production of the score.

MICRO-PK: Any psychokinetic effect that requires statistical analysis for its demonstration. Sometimes used to refer to PK that has as its target a quantum mechanical system.

NEAR-DEATH EXPERIENCE (NDE): A predominantly visual experience undergone by persons who either seem to be at the point of death but then recover, or who narrowly escape death (as in a motor car accident) without being seriously injured. NDEs often incorporate out-of-body experiences.

OPEN DECK: A procedure for generating a target order in which each successive target is chosen at random independently of all the others; thus, for example, in the case of a standard deck of ESP cards whose target order is "open deck," each type of symbol is not necessarily represented an equal number of times.

OUT-OF-THE-BODY EXPERIENCE (OBE): An experience, either spontaneous or induced, in which one's center of consciousness seems to be in a spatial location outside of one's physical body.

PARANORMAL: Term for any phenomenon that in one or more respects exceeds the limits of what is deemed physically possible according to current scientific assumptions.

PARAPSYCHOLOGY: The scientific study of certain paranormal or ostensibly paranormal phenomena, in particular, ESP and PK.

PERCIPIENT: The individual who experiences or "receives" an extrasensory influence or impression; also, one who is tested for ESP ability.

POLTERGEIST: A disturbance characterized by physical effects of ostensibly paranormal origin, suggesting mischievous or destructive intent. These phenomena include such events as the unexplained movement or breakage of objects, loud raps, electrical disturbances, and the lighting of fires.

POSITION EFFECT (PE): The tendency of scores in a test of psi to vary systematically according to the location of the trial on the record sheet.

PRECOGNITION: A form of ESP involving awareness of some future event that cannot be deduced from normally known data in the present.

PROCESS-ORIENTED: Term for research whose main objective is to determine how the occurrence of psi is related to other factors and variables.

PROOF-ORIENTED: Term for research whose main objective is to gain evidence for the existence of psi.

PSI: A general term used either as a noun or adjective to identify ESP or PK.

PSI-HITTING: The use of psi in such a way that the target at which the subject is aiming is "hit" (correctly responded to in a test of ESP, or influenced in a test of PK) more frequently than would be expected if only chance were operating.

PSI-MISSING: The use of psi in such a way that the target at which the subject is aiming is "missed" (responded to incorrectly in a test of ESP, or influenced in a direction contrary to aim in a test of PK) more frequently than would be expected if only chance were operating.

PSYCHOKINESIS (PK): Paranormal action; the influence of mind on a physical system that cannot be entirely accounted for by the mediation of any known physical energy.

RANDOM EVENT GENERATOR (REG): An apparatus (typically electronic) incorporating an element capable of generating a random sequence of outputs; used in automated tests of psi for generating target sequences; in tests of PK, it may itself be the target system that the subject is required to influence; also called a random number generator (RNG).

RECURRENT SPONTANEOUS PSYCHOKINESIS (RSPK): Expression for paranormal physical effects that occur repeatedly over a period of time; used especially as a technical term for poltergeist disturbances.

REMOTE VIEWING: A term for ESP used especially in the context of an experimental design wherein a percipient attempts to describe the surroundings of a geographically distant agent.

RESPONSE BIAS: The tendency to respond or behave in predictable, nonrandom ways.

RETROACTIVE PK: PK producing an effect backward in time; to say that event A was caused by retroactive PK is to say that A would not have happened in the way that it did had it not been for a later PK effort exerted so as to influence it; sometimes abbreviated as retroPK; also referred to as backward PK or time-displaced PK.

RUN: A fixed group of successive trials in a test of psi.

SHEEP-GOAT EFFECT (SGE): The relationship between one's acceptance of the possibility of ESP's occurrence under the given experimental conditions and the level of scoring actually achieved on that ESP test; specifically, the tendency for those who do not reject this possibility ("sheep") to score above chance and those who do reject it ("goats") to score below chance.

SPONTANEOUS CASE: Any psychic occurrence that takes place naturally, and is often unanticipated--psi in a real-life situation, as opposed to the experimentally-elicited psi phenomena of the laboratory.

STACKING EFFECT: A spuriously high (or low) score in a test of ESP when two or more percipients make guesses in relation to the same sequence of targets; it is due to a fortuitous relationship occurring between the guessing biases of the percipients and the peculiarities of the target sequence.

TARGET: In a test of ESP, the object or event that the percipient attempts to identify through information paranormally acquired; in a test of PK, the physical system, or a prescribed outcome thereof, that the subject attempts to influence or bring about.

TELEPATHY: The paranormal acquisition of information about the thoughts, feelings, or activity of another conscious being.

TRIAL: An experimentally defined smallest unit of measurement in a test of psi: in a test of ESP, it is usually associated with the attempt to gain information paranormally about a single target; in a test of PK, it is usually defined in terms of the single events to be influenced.

VARIANCE: A statistic for the degree to which a group of scores are scattered or dispersed around their average; formally, it is the average of the squared deviations from the mean; in parapsychology, the term is often used somewhat idiosyncratically to refer to the variance around the theoretical mean of a group of scores (e.g., MCE) rather than around the actual, obtained mean. Run-Score Variance. The variance around the mean of the scores obtained on individual runs. Subject Variance. The variance around the mean of a subject's total score.