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 VIII CHI SQUARE TEST OF REVISED KNOWNS VERSUS
UNKNOWNS ON THE BASIS OF COLOR
Color
Number of
KNOWNS
Adjusted
Number of
KNQWNS (K)
Number of
UNKNOWNS (n) K
White
Metallic
Not stated
Orange
Red
Yellow
Green
Blue
Other
281
298
189
117
92
90
32
29
158
95
101
64
39
31
30
11
10
53
Total 1286 434 434
3.04
6.19
0.06
2. 56
0. 13
0.03
0 . 8 2
0 . 5 7
13.40
•II
D e g r e e s of f r e e d o m
5%
1%
14. 1
18. 5
I
"t.
.4:-.
70