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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.
“Punch”14 pages
t \ f Graphical Presentation Graphical representation of the important information contained in the tables is presented in Figures 1 through 38. These figures present the distributions of the important variables only by the total number of cases' in each identification category, since no significant differences were found between the distributions of "Certain" and "Doubtful" identifications of objects with respect to the variables. A chronological study'of these figures will afford a broad picture of the tabulated information, without the necessity of a detailed study of the tables. A critical examination of the figures will show that no trends, patterns, or correlations are to be found, with the exception of Figures 18 through 30. The apparent similarity of the distributions shown by these mirror graphs, Figures 18 through 23, was tested by statistical methods which showed that there ,was a low probability that the distributions of the KNOWNS and UNKNOWNS by these characteristics were the same. These tests and their interpretation are discussed in the following section. For purposes of this study, the strategic areas, shown in Figures 32 through 38, and Tables A223 through A240, Appendix A, were designated on the basis of concen- tration of reports of OBJECT SIGHTINGS in an area. No other interpre- tation of the tables or remaining charts was deemed necessary. Advanced Study of the Data It was recognized that the lack of any patte-rns or trends, as shown by the tabulations and graphs, provided an insecure basis for drawing definite ^Conclusions. Accordingly, shortly before the sorting and tabulation pro- gram was concluded, a program of study of the data was developed to utilize statistical and other mathematical methods, which could lead to a more concrete interpretation of the problem. Position of the Sun Relative to the Observer The first thing that was done was to calculate the angle of elevation of the sun above the horizon and its bearing from true north as seen by the observer at the time of each sighting. With this information, it could then be determined whether there was a possibility that the reported object could have been illuminated by light from the sun. In addition, it could be determined whether an object could be a mock sun ( sun dog) or whether there was a possibility of specular reflection from an aircraft at the posi- tion of the object, -which would give the appearance of a "flying disc". A program of computation was set up and carried out to obtain the angle of elevation and the bearing of the sun for each sighting. All informa- tion needed for this calculation was available on the deck of IBM cards. 16
Report, cited by the archive. The PDF is mirrored here; the original link is under it. 309 pages are in the text index: search them above, or from the library's search.