Project Blue Book Special Report No. 14: Analysis of Reports of Unidentified Aerial Objects

For machine manipulation, it was desirable to be able to select the
sample of cards (all reports, all sightings, or all phenomena) to be in-
cluded in a particular study. The concept of a SIGHTING IDENTIFICATION
NUMBER was evolved to fill this desire. Using one column of the IBM
card, and the correlated working papers, the code for this function was
developed. Multiple punching elirninated the need to use several columns
for discrete expression of the variations., Selection of the proper number
in this column thus permitted selection of the desired sample of cards.
Evaluation of Individual Reports
of sighting reports was recognized as a crucial step in the
preparation of data for statistical treatment; inconsistent evaluations would
have invalidated any conclusions to be derived from this study. A method
of evaluation was, therefore, determined simultaneously with the develop-
ment of the questionnaire, the coding system, and the work sheet. It is
emphasized that all phases of evaluation, even including the tedious prep-
aration of the original data for statistical treatment, were entrusted only
to selected, specially qualified scientists and engineers.
Evaluation consisted of a standardized procedure to be followed for:
(1) the deduction of discrete facts, from data which depended on human im-
pressions rather than scientific measurements, (2) the rating of the ob-
server and his report as determined from available information, and (3) the
determination of the probable identification of the phenomenon observed.
Categories of identification, established upon the basis of previous experi-
ence, were as follows:
Balloon
Astronomical
Aircraft
Light phenomenon
Birds
Clouds, dust, etc.
Insufficient information
Psychological manifestations
Unknown
Other
The first step in evaluation, the deduction of discrete facts from
subjective data, required certain calculations based on the information
available in the sighting report. An example was the finding of the approxi-
mate angular velocity and acceleration of the object or objects sighted.
Care was taken during this phase of the work to insure against ^he deduc-
tion of discrete facts not warranted by the original data. Thus, even
though there was a complete lack of any valid evidence consisting of
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