The Scope of Parapsychological Study
Most sciences try to explain observable phenomena;
parapsychology tries to observe unexplainable phenomena.[1]
According to the Parapsychological Association (of America) parapsychology is limited in its scope to the study of three main types of paranormal phenomena: Mental Phenomena, Physical Phenomena, and Survival Phenomena
1.Mental Phenomena
Often described as Extrasensory Perception this type of phenomena includes unusual mental states or abilities involving some kind of information transfer occurring outside the confines of one's five senses:
1.1 Telepathy
The paranormal acquisition of information concerning the thoughts, feelings or activity of another person
1.2 Clairvoyance
Clairvoyance is different from telepathy in that the information gained by a clairvoyant is assumed to derive directly from an external physical source, and not from another person's mind. Clairvoyance does not necessarily contain precognitive knowledge.
1.3 Remote Viewing
A neutral term for experiments in which the subject tries to describe a distant location or the environs of a distant agent.
1.4 Precognition
A person perceives information about future places or events before they happen (as distinct from merely predicting them based on reasoning and current knowledge).
1.5 Retrocognition
Also called Postcognition---the ability to observe the past of an object, place, or occurrence through paranormal means. Psychometry and Past Life Regression can both be considered types of retrocognition.
1.7 Psychometry
A psychic holds an object in his or her hands in order to obtain information about the object or its owner. In recent times the term has been superseded in favour of Token-Object Reading, due to the confusion with a psychological term, 'psychometry'.
1.8 Xenoglossy
The phenomenon in which a person is able to speak a language that he or she could not have acquired by natural means. For example, a person who speaks German fluently and like a native, but has never studied German, been to a German-speaking country, or associated with German-speakers, would be said to exhibit xenoglossy.
1.9 Mediumism or Channeling
A medium, spirit medium or channeller is an individual who has the ability to receive messages from spirits or the ability to channel such entities---that is, write or speak in the voice of these entities rather than in the medium's own voice.
1.10 Clairaudience
From late 17th century French clair (clear) and audience (hearing)---a form of extra-sensory perception wherein a person acquires psychic knowledge primarily by auditory means. Clairaudience is essentially the ability to hear in a paranormal manner, as opposed to paranormal seeing (clairvoyance) and feeling (clairsentience).
1.11 Clairsentience
From the French clair, 'clear',.and sentience, 'feeling'---a form of extra-sensory perception wherein a person acquires psychic knowledge primarily by means of feeling.
1.12 Possession
Spiritual possession occurs when a spirit, god, demon, or other disincarnate entity takes control of a body which is not its own.
2. Physical Phenomena
This type of phenomenon includes unusual physical occurrences caused by the mind directly influencing its physical surroundings:
2.1 Psychokinesis (PK)
Also known as telekinesis (TK), it is the paranormal ability of the mind to influence matter or energy without the use of any currently known type of physical means. For instance, psychokinesis might be used to distort or move an object, lift a table, or influence a random number generator.
2.2 Direct Voice
Known also as independent direct voice, it involves a voice reportedly originating in space without visible source or agency.
2.3 Poltergeists
German for noisy ghost, this is a term used to describe a spirit or ghost that manifests itself by moving and influencing inanimate objects.
2.4 Stigmata
The bodily marks, sores, or sensations of pain in locations corresponding to the crucifixion wounds of Jesus.
2.5 Bilocation
The act of appearing or being in two or more locations simultaneously.
2.6 Paranormal Vanishing
Reputed unexplainable disappearance of objects, animals or people without apparent reason or cause, or in circumstances that could indicate the involvement of the paranormal.
2.7 Materializations
The creation or appearance of matter from nowhere and out of nothing.
2.8 Psychic Healing
aka, Faith healing, Divine healing, Spiritual Healing. The use of paranormal means in treating disease, sometimes accompanied by the refusal of modern medical techniques
2.9 Synchronicity
The experience of two or more occurrences (beyond coincidence) in a manner that is logically meaningful---but inexplicable---to the person or persons experiencing them. Such events would also suggest an underlying pattern in order to satisfy the definition of synchronicity.
2.10 Dowsing
Dowsing, sometimes called Divining or Water Witching, is a generic term for practices which proponents claim empower them to find water, metals, gem stones and hidden objects over a piece of land or a map, usually through fluctuations of apparatus including a Y-shaped twig, rods or pendulum.
3. Survival Phenomena
This type of phenomena deals with the survival of consciousness after physical death and includes:
3.1 Ghosts
The apparition of a deceased person which frequently carries the deceased person's likeness and is experienced in association with the person's former habitats.
3.2 Electronic voice phenomena (EVP)
Anomalous voice or voice-like sounds which believers in the paranormal say have been captured on a variety of recorded media. Typically they are brief, the length of a word or short phrase.
3.3 Out-Of-Body Experience (OBE or OOBE)
Also known as Astral Projection, an experience that typically involves a sensation of floating outside of one's body and, in some cases, seeing one's physical body from a place outside one's body (Autoscopy).
3.4 Reincarnation
Literally 'to be made flesh again'---the notion that some essential part of a living being (or in some variations, only human beings) can survive death in some form, with its identity wholly retained, to be reborn in a new body.
3.5 Near-Death Experiences (NDEs)
A type of experience reported by a person who nearly died, or who experienced clinical death and then revived.
[1] Robert Todd Carroll (1945–2016), 'The Skeptic's Dictionary', entry on 'Parapsychology'