Defining parapsychology is not an easy task. The researchers who would have been expected to clarify things have actually contributed to the problem. Most definitions of parapsychology tend to emphasize negative aspects, defining it according to what it is not rather than what it is. The absence of a substantive definition is one of the things that prevents parapsychology from being taken more seriously.
Read Article: Introduction to Parapsychology, Psychics, and the Paranormal