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

MULTIPLE OBSERVATION was identified with the .00 subserial number.
As an example, a MULTIPLE OBSERVATION consisting of six sighting
reports would have the following serial numbers:
1132.00 representing the best report and observer
1132.01 representing an additional observer
1132.02 representing an additional observer
1132.03 representing an additional observer
1132.04 representing an additional observer
1132.05 representing an additional observer
During the course of the transcription of the data to machine card
form, it became obvious that certain reports could have been independent
observations of the same phenomenon. So, if the presentation of an
analysis based on one report for each sighting -was valid (the concept of
UNIT SIGHTINGS), a presentation of an analysis based on one report for
each phenomenon should be .valid also. Further, the examination of data
relating to the actual number of phenomena was considered to be the proper
basis for assessing the probability of technological developments outside
the range of present-day scientific knowledge. Therefore, a designation of
OBJECT SIGHTINGS was established, with the following definition:
OBJECT SIGHTING - (1) The group of,reports consisting of
one report for each phenomenon. (2) The
questionnaire, work sheet, and IBM card
representing a report for each phenomenon
accepted for the statistical study.
In brief review, ALL SIGHTINGS refer to all reports, UNIT SIGHTINGS
refer to actual sightings, and OBJECT SIGHTINGS refer to the assumed
number of phenomena.
It must be recognized that the process of identifying OBJECT
SIGHTINGS was deductive, while that for UNIT SIGHTINGS was definitive.
A conservative approach was adopted in the determination of OBJECT
SIGHTINGS, using the factors of date and time of observations, location
of observers, duration of observations, and range, bearing, track direc-
tion, and identification of the phenomena. Any error of selection of OBJECT
SIGHTINGS will tend to be in the direction of reducing the actual number of
phenomena observed (several instances of UNIT SIGHTINGS that might be
one OBJECT SIGHTING were noted, but the evidence was not conclusive
enough to justify consolidation of the reports).
Following the determination of OBJECT SIGHTINGS, a series of
serial numbers, called the INCIDENT SERIAL NUMBERS, was established
to facilitate any future study of a specific object sighting. Each reported
sighting that relates to an OBJECT SIGHTING received the same incident
serial number, a four-digit code paralleling the major serial number
series.