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.
Total Less Unknown Per Cent 30 25 20 i 15 10 5 seconds or less 6-10 seconds 11-30 seconds 3 1 - 6 0 seconds 61 seconds 5 minutes 6-30 minutes More than 3 0 minutes Not stated 5 i Unknown Per Cent 10 15 20 i 25 i 30 i FIGURE 21 COMPARISON OF KNOWN AND UNKNOWN OBJECT SIGHTINGS BY DURATION , 1 9 4 7 - 1 9 5 2 A-74 99
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.