Invigilators serve as hopeful witnesses in an investigation.

Ghost hunting involves a number of overlapping, but discrete ways of thinking about how the supernatural bleeds into the natural world. We simplify these ways of thinking by organizing them into three modes of inquiry: investigation (emphasizing methodology and quality of evidence in the search for ghosts); invigilation (emphasizing the searchers’ disposition and attunement as a factor in the search); and mediumship (emphasizing the psychical potential of the searchers, whether wielded or not).

The investigator, invigilator, and medium fall along a spectrum in which what counts as actionable evidence is increasingly dematerialized. The investigator hopes for a material trace, a record of the encounter; the invigilator is watchful and tuned to the auguries of mood; the medium episodically pierces the spectral plane (or attempts as much). Only invigilators are assured of success: they watch and report on the scene as it is, including themselves as embodied agents within the scene.

The concept of invigilation is inspired by the Victorian parapsychologists who studied and worked alongside mediums to advance their research in the second half of the nineteenth century. Invigilators are receptive to nontraditional, non-materialist interpretations of paranormal phenomena; they cultivate a willful credulity that serves as a bridge between the ostensibly incompatible worldviews of the scientist and medium. Invigilators are positively biased towards the in-world belief system espoused by their colleagues, even if they suspect that those beliefs are only loosely supported (or simply unsupported) by the evidence discovered in their investigations.

A note on the poetic significance of invigilation. It calls to mind formal proctoring, watching over students taking an exam. Vigilance against cheating. But for our purposes, the term is also pregnant with vigil: a period of waiting marked by hope. A church vigil enforces a certain discomfort, often staged in a way that produces fatigue—so that the hopeful watcher is transformed by the watching. A heady mix of chanting and incense help the transformation along. We can think of a vigil as a purposeful, performative deterioration of common sense for the sake of belief, and of the invigilator as a canny celebrant.