Project Blue Book Special Report (second copy)

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.

100-
90-
. 80-
7 0 -
60-
4-
C
d)
O 50-
£ 4 0 -
30-
20-
10-
0_
Not
stated
Other
Flame
.enticularconico
or teardrop
Elliptical
23.5%
/s
11.2 %
\AstronomicaK
N\\\\\\W
1
Aircraft
I
^ ^
Balloon/ Insuf. info:
\
ooooax
•A-
Unknown
-
4.8%
WT
W o \
\\ >
\
A47.0 7<A
Shape i
10 2 0 30 40 -50 60
Evaluation in Per Cent
i
70 8 0 i
90 100
FIGURE 15 DISTRIBUTION OF OBJECT SIGHTINGS BY SHAPE OF OBJECTS) REPORTED WITH
EVALUATION DISTRIBUTION FOR EACH SHAPE .GROUP A-7493