Scientific Evidence for UFOs
UFO sightings are largely documented anecdotally. Most scientists don't accept such input as evidence. But at a 1969 AAAS symposium on UFOs, MIT physicist Philip Morrison said: "Absence of humans in the data link is [not] the criterion for good evidence...From the point of view of drawing inferences about events, a witness is simply an extraordinarily subtle and complex instrument of observation."
R. V. Jones, head of British MI6 during WW II, used what he called touchstones to decide if a report should be taken seriously, i.e., if it contained information he could rely on. This gave confidence that other information in the report was likely true. In the UFO context, consciously recalled details, supplementary witnesses, missing time, and physical phenomena are touchstones.
Other evidence for UFOs includes simultaneous radar-visual reports, photographs, and ground traces from CE2 events.