(Analysis of Reports of Unidentified Aerial Objects)

This CIA-released copy of Project Blue Book Special Report No. 14 is dated 5 May 1955 and comes from the Air Technical Intelligence Center at Wright-Patterson Air Force Base. It is a statistical analysis of about 4,000 unidentified aerial object reports from 1947 through 1952, coded onto IBM punched cards with the help of a panel of scientists. The report concludes that such objects were highly unlikely to be technological developments beyond present-day scientific knowledge. It also found no valid evidence of physical matter.

TABLE VI CHI SQUARE TEST OF KNOWNS VERSUS UNKNOWNS ON THE BASIS OF SPEED

Speed	Number of KNOWNS	Adjusted Number of KNOWNS(K)	Number of UNKNOWNS(n)	X2(K-n)2/K
Stationary	249	61	53	1.05
Less than 100mph	154	38	26	3.79
100 to 400mph	181	45	58	3.76
Over 400mph	403	99	145	21.37
Meteor-like	83	20	16	0.80
Not stated	695	171	136	7.16
Total	1765	434	434	37.93
Degrees of freedom 5
5% 11.1
1% 15.1