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.
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Upon completion of final identifications, all data were transferred to
IBM cards, preparatory to analysis.
ANALYSIS OF THE DATA
Broadly stated, the problem at this point consisted of the judicious
application of scientific methods of categorizing and analyzing the sub-
jective data in reports of sightings of unidentified aerial objects. It was
recognized that an approach to this problem could best be made by a sys-
tematic sorting and tabulation program to give frequency and percentage
distributions of the important characteristics of sightings. A suggestion
that an attempt be made to anticipate all questions that might be asked in
the future about a sighting or a group of sightings, and to provide answers,
was rejected. The systematic approach also made it possible to develop
a detailed reference manual of the attributes of the sightings included in
this study.
Thus, at the beginning of the analysis, a detailed plan was developed
for sorting, counting, and tabulating the information from the punched-card
abstracts of reports of sightings. It was believed at the time, and later
substantiated, that the results of the program for sorting and tabulating
would serve as a guide for the more sophisticated treatment involving
statistical methods.
Also, it was anticipated that any patterns or trends that might be
found could be subjected to concentrated study in the hope of discovering
significant information relating to the characteristics of "flying saucers".
Further, it was believed that these trends could serve as certain of the
criteria of validity for any concepts (models) developed in the attempt to
discover a class of "flying saucers".
The three parts of this study (1) the sorting and tabulation program,
(2) the advanced study of the results of that program, and (3) the investiga-
tion of the possibility of conceiving a model of a "flying saucer" from
descriptions reported, are discussed in sections entitled "Frequency and
Percentage Distributions by Characteristics", "Advanced Study of the Data"
and "The 'Flying Saucer1 Model".
Frequency and Percentage Distributions by Characteristics
The original conception of this study assumed the availability of
sufficient data to describe adequately the physical appearance, maneuver
characteristics, range, direction, and probable path of the object or
objects observed. However, familiarity with the data, acquired during the
14 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.