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Project Blue Book Special Report No. 14: Analysis of Reports of Unidentified Aerial Objects

United States Air Force, Air Technical Intelligence Center · 1955-05-05 · 309 pages · text from the file's own layer

Special Report No. 14 was issued by the U.S. Air Force's Air Technical Intelligence Center on 5 May 1955. It is a statistical study of about 4,000 reports of unidentified aerial objects from June 1947 to December 1952. The reports were reduced to IBM punched cards and analyzed with methods including chi square tests. The report concludes that the reports it examined are very unlikely to represent technology beyond present scientific knowledge, and it notes that no case produced valid physical evidence.

meteorological phenomena like small tornadoes, were collected into a
category called OTHER. A separate category for the uncommon natural
phenomena associated with light reflections or refractions, such as mirages,
sun dogs, inversion-layer images, and distortions caused by airborne ice,
was established with the title of LIGHT PHENOMENON. Categories for
INSUFFICIENT INFORMATION, PSYCHOLOGICAL MANIFESTATIONS, and
UNKNOWN were provided for the sightings that could not be fitted into the
preceding identifications. An explanation of their use follows:
INSUFFICIENT INFORMATION - This identification category
was assigned to a report when, upon final con-
sideration, there was some es-s^ui±ijJLitem of
information mis sing, or there was enough
doubt about what data were available to disallow
identification as a common object or some
natural phenomenon. It is emphasized that this
category of identification was not used as a
convenient way to dispose of what might be
called "poor unknowns", but as a category for
reports that, perhaps, could have been one of
several known objects or natural phenomena.
No reports identified as INSUFFICIENT INFORMA-
TION contain authenticated facts or impressions
concerning the sighting that would prevent its
being identified as a known olbject or phenomenon;
PSYCHOLOGICAL MANIFESTATIONS - This identification
category was assigned to a report when,
although it was well established that the ob-
server had seen something, it was also
obvious that the description of the sighting
had been overdrawn. Religious fanaticism, a
desire for publicity, or an over-active imagi-
nation were the most common mental ab_£-E—
rations causing this type of report;
UNKNOWN —. This designation in the identification code was
assigned to those reports of sightings wherein
the description of the object and its maneuvers
could not be fitted to the pattern of anyjenown
object or phenomenon.
For the purposes of this study, two groups of identifications were
recognized, the KNOWNS (including all identification categories except the
UNKNOWNS) and the UNKNOWNS. .
All possible identifications provided in the code system, except
INSUFFICIENT INFORMATION and UNKNOWN, could be assigned accord-
ing to two degrees of certainty, designated "Certain" and "Doubtful".
12

Cases discussed

About this file

Analysis, from the classic collection. The PDF is mirrored here; the original link is above. 309 pages are in the text index: search them above, or from the library's search.