What is a Poltergeist?
As a paranormal investigator, a poltergeist is any haunting that shows a level of cognizance. In short, any spirit that can interact in our world and shows some degree of self-awareness is considered a poltergeist. Consider an EVP session, if the spirit you are attempting to communicate with chooses to answers your questions with the appropriate responses in real time, this interaction shows that the spirit has a level of self-awareness. By my definition, any ghost that can participate in spirit communication, move psychical objects, react to current events, and exhibit the ability to choose is a poltergeist. When you experience this kind of haunting, the only question is how classify the poltergeist by the level of activity experienced.