As a psychic, I might have a slightly biased opinion of the place of psychics in paranormal investigations. My thought is that the psychic is just as valuable as the hard evidence. A good psychic can add depth and dimension to the investigation and can open fields of exploration that could not happen when instruments alone are used or valued. While it’s true that psychic input on it’s own is not hard evidence, when it is linked to historic or photographic documentation that the psychic didn’t have knowledge of, or if there are independent experiences over time that support the psychic impression, then those impressions can be taken as accurate and do have weight in the investigation.
The psychic can add the personal and the art to the investigation, bringing in the personality of the entities, and the thoughts, emotions and lives of those involved. In my opinion, a good, well rounded investigation consists of both scientific and psychic documentation and techniques.
Let me know your thoughts!