Documents / Report
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.
“Punch”14 pages
SUMMARY Reports of unidentified aerial <5bjects (popularly termed "flying saucers" or "flying discs", have been received by the U. S. Air Force since mid-1947 from many and diverse sources. Although there was no evidence that the unexplained reports of unidentified objects constituted a threat to the security of the U. S. , the Air Force determined that all reports of unidentified aerial objects should be investigated and evaluated to determine if "flying saucers" represented technological developments not known to this country. V In order to discover any pertinent trends or patterns inherent in the data, and to evaluate or explain any trends or patterns found, appropriate methods of reducing these data from reports of unidentified aerial objects to a form amenable to scientific appraisal.were employed. In general, the original data upon -which this study was based consisted of impressions and interpretations of apparently unexplainable events, and seldom contained reliable measurements of physical attributes. This subjectivity of the data presented a major limitation to the drawing of significant conclusions, but did not invalidate the application of scientific methods of study. . The reports received by the U. S. Air Force on unidentified aerial objects were reduced to IBM punched-card abstracts of the data by means of logically developed forms and standardized evaluation procedures. Evaluation of sighting reports, a crucial step in the preparation of the data for statistical, treatment, consisted of an appraisal of the reports and the subsequent categorizing of the object or objects described in each report. A detailed description of this phase of the study stresses the careful attempt to maintain complete objectivity and consistency. Analysis of the refined and evaluated data derived from the original reports of sightings comprised (1) a systematic attempt to ferret out any distinguishing characteristics inherent in the data or any of their segments, (2) a concentrated study of any trends or patterns found, and (3) an attempt to determine the probability that any of the UNKNOWNS represent obser- vations of a class, or classes, of "flying saucers". The first step in the analysis of the data revealed the existence of certain apparent similarities between cases of objects definitely identified and those not identified. Statistical methods of testing were applied -which indicated a low probability that these apparent similarities were signifi- cant. An attempt to determine the probability that any of the UNKNOWNS represent observations of a class, or classes, of "flying saucers" neces- sitated a thorough re-examination and re-evaluation of cases of objects not originally identified; this led to the conclusion that the probability was very small. v v n
Report, cited by the archive. The PDF is mirrored here; the original link is under it. 309 pages are in the text index: search them above, or from the library's search.