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.

ro
100
90
60
70
<_ 60
c
0)
U 50
No. of object sightings
2199 79 43 186 169 121
Q. 40
30
20
10
0
1501
" f t
i
-
-
Excellent
Good
Doubtful
Poor
V
\
\
\
\
\
1
' •
1
/
1
/
1
1
1
I
1
1
1
1
1
1
1
1
1
1
1
1
1
t
\
\ ( .
\
V
\
\
4
• *
\ '
\
\
\
\
\
\
\
)
—
-
100
90
80
70
60
50
40
30
2 0
H 10
All years 1947 1948 1949 1950 951 1952
FIGURE 9 DISTRIBUTION OF OBJECT SljGHTINGS AMONG THE FOUR SIGHTING RELIABILITY
GROUPS FOR ALL YEARS AND EACH YEAR
A-74 87