Documents / Report
This is Project Blue Book Special Report No. 14, "Analysis of Reports of Unidentified Aerial Objects," Project No. 10073, dated 5 May 1955. The study reduced about 4,000 sighting reports received by the U.S. Air Force between June 1947 and December 1952 to IBM punched cards and analyzed them statistically, including chi square tests comparing knowns with unknowns. It concludes that the reports very probably do not represent technological developments beyond present scientific knowledge, and it notes that no case produced 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
Report, cited by the archive. 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.