CIA-UAP-015, Project Blue Book Special Report No. 14 (Analysis of Reports of Unidentified Aerial Objects)

I
I SUMMARY
I
I Reports of unidentified aerial objects (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
I a threat to the security of the U.S., the Air Force determined that all
rep,orts of unidentified aerial objects should be fovestigated and evaluated
to d,etermine if "flying saucers". represented technological developments
not known to this country.
I In order to discover any pertinent trend or pattern inherent in the
data, and to evaluate or explain any trend or pattern found, appropriate
I methods of reducing these data from reports of unidentified aerial objects
to a form amenable to scientific' appraisal were employed. In general, the
I 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
I presented a 'major limitation to the drawing of significant conclusions, but
did not invalidate the application of scientific methods bf study.
I 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
I for statistical treatment, consisted of an appraisal of the reports and· the
subsequent categorization of the object or objects described in each report.
A detailed description of this phase of the study stresses the careful
I attempt to maintain complete objectivity and consistency.
I Analysis of the refined and evaluated data derived from the original
reports of sightings consisted of (I) a systematic attempt to ferret out any
distinguishing characteristics _inherent in the data of any of their segments,
I (2) a concentrated study of any trend or pattern found, and (3) an attempt
to determine the probability that any of the UNKNOWNS represent observa.:.
tions of technological' developments not known to this country.
I The first step in the 'analysis of the data revealed the existence of
I
certain apparent similarities between cases of objects definitely identified
.i.nd those not identified. Statistical methods of testing when applied indicated
a low probability that these apparent similarities were significant. An
attempt to determine the probability that any of the UNKNOWNS represeri'ted
observations of technological developments not known to this country necessi
I tated a thorough re-examination and re-evaluation of the cases of objects not
originally identified; this led to the conclusion that this probability was very
small.
I
I The special study which resulted in this report (Analysis of Reports
of Unidentified Aerial Objects, 5 May 1955) started in 1953. To provide the
study group with a complete set of files, the informatio~ cut-off date was
established as of the end of 1952. It will accordingly be noted that the
statistics contained in all charts and tables in this report are terminated
I vii
I
I