It's about kind of experience rather than kind of person, though, isn't it? So, it's always aliens. First kind is a polite commnent about the cut of your suit floating through the ether on a cloudless night. Second kind is the faint sensation that somewhere a man or woman with a face not unlike yours but a dusting of freckles across the bridge of his or her nose was kissed lightly on the ear by somebody who came to Earth to study but has trashed his sublight radio and buried his ray gun.
I thought an encounter of the first kind was being chased along lonely mountain road by a demon-possessed truck.
Second kind was having your leg chewed off by a Great White.
However: Publicity for the film distinguished the varying levels of encounters with aliens:
CLOSE ENCOUNTER
of the First Kind
Sighting of a UFO
CLOSE ENCOUNTER
of the Second Kind
Physical Evidence
(of an Alien Landing)
CLOSE ENCOUNTER
of the Third Kind
Contact (with Aliens)
Look, if it's unidentified... and, y'know, in mid-air... then it qualifies. Sundogs, marsh gas, weather balloons—they're all UFOs, if you don't know what they are.
Mr. Fear is being skeptical. Is it true Jack? Can you doubt the existence of ETs when they're categorised by such an obviously respectable scientist as Keifer? Surely not. UFOs are ALIENS, those other things are just Unidentified Objects, that, y'know, Fly...