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.
O» Total Less Unknown Per Cent 40 35 30 25 20 15 10 i i i i i i i 5 0 0 5 10 Stationary Less than 100 mph 100 to 400 mph More than 4 0 0 mph Meteor-like Not stated Unknown Per Cent 15 20 25 30 35 40 I I I I I L_ FIGURE 20 COMPARISON OF KNOWN AND UNKNOWN OBJECT SIGHTINGS BY SPEED, 1947-1952 \ ' A-749§
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.