Lehmann notes how Alice was present at the scene of all recorded poltergeist activity, with her father present in some instances, hypothesizing that the poltergeist activity centers around her, with her father perhaps acting as a catalyst or cooperating agent. The question he asks is whether the activity is conscious or unconscious, drawing to the theory that paranormal activity is a product of the unconscious mind. Psychokinesis is also suggested as a possible explanation.
See: “The House of Knocks and Bumps,” pg. 7, page 1, page 2
Manuscript, “The House of Knocks and Bumps,” Daniel Lehmann, pg. 8, Folder “Baltimore Poltergeist,” Box D, Eileen J. Garrett Parapsychology Foundation collection, Collection 331, Special Collections, University of Maryland, Baltimore County (Baltimore, MD).