Documents / FOIA release
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.
“Harder”1 page
Read from the scan by GLM-OCR; expect the odd misread word.
In five of the six cases, the probability is less than 1 per cent that the distributions are the same. In the sixth case, Light Brightness, the classifications are too nebulous to be of real value. However, these tests do not necessarily mean that the UNKNOWNS are primarily "flying saucers" and not aircraft, balloons, or other known objects or natural phenomena. The UNKNOWNS might still be unidentified KNOWNS if either of the following cases occurred: (1) The characteristics which were observed for the UNKNOWNS were different from those observed for the KNOWNS because of the psychological make-up of the observer or because of atmospheric distortion. This assumes the distribution of objects in KNOWNS and UNKNOWNS is the same. (2) The UNKNOWNS may be known objects in different proportions than the group identified as KNOWNS. (That is, a greater percentage of the UNKNOWNS could be aircraft than the percentage of aircraft in the identified KNOWNS.) The second case is the more probable one. In this connection, it is interesting to note the factors which contributed to a large chi square result in the tests made above: ## (1) Color The major contribution to chi square in color is from the color green. There is a large excess of green sightings among the KNOWNS over the UNKNOWNS. Of the 130 known objects in this classification, 98 are astronomical, and are due mostly to the green fireballs reported from the Southwest U. S. ## (2) Number The large chi square is due to a greater proportion of UNKNOWNS in the multiple object classification. Apparently these are harder to identify. ## (3) Shape In this case, there is a higher percentage of UNKNOWNS in the rocket-aircraft-shape classification. These might be familiar objects for which unusual maneuvers were reported. There is a higher percentage of KNOWNS in the flame and in the meteor- or comet-shape category, which in both cases appears to result mainly from excesses of astronomical sightings.
FOIA release, from the cia-readingroom collection. The PDF is mirrored here; the original link is above. The text was read from the page images by GLM-OCR; expect the odd misread word. 312 pages are in the text index: search them above, or from the library's search.