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.

TABLE XII
Speed
Stationary
Less than 100 mph
100 to 400 mph
Over 400 mph
Meteor-like
Not stated
CHI SQUARE TJ
UNKNOWNS ON
Number of
KNOWNS
196
128
156
291
2 4
491
£ST OF REVISE
THE BASIS OF
Adjusted
Number of
KNOWNS (K)
66
43
53
98
8
166
D KNOWNS VERt
SPEED
Number of
UNKNOWNS (n)
53
26
58
145 1
16}
136
5US
X 2
( K - n ) 2
K
2. 56
6.72
0.47
~> Q C A
do. 54
5.42
f
Total 1286 434 434 43.71
Degrees of freedom
5%
1%
9.5
13.3
74