Project Blue Book Special Report (second copy)

records include condensations of all individual sighting reports, and the
IBM cards used in vaTious phases of the study.
ORIGIN AND NATURE OF DATA
Reports of sightings were received by the U. S. Air Force ftom a
representative cross secjtion of the population of the U. S. , and varied
widely in completeness and quality. Included were reports from reputable
scientists, housewives, farmers, students, and technically trained mem-
bers of the Armed Forces. Reports varied in. length from a few sentences
stating that a "flying saucer" had been sighted, to those containing thou-
sands of words, including description, speculation, and advice on how to
handle the "problem of the 'flying saucers'". Some reports were of high
quality, conservative, and as complete as the observer could make them;
a few originated from people confined to mental institutions. A critical
examination of the reports revealed, however, that a high percentage of
them was submitted by serious people, mystified by what they had seen and
motivated by patriotic responsibility.
Three principal sources of reports were noted in the preliminary
review of the data. The bulk of the data arrived at ATIC through regular
military channels, from June, 1947, until the middle of 1952.
A second type of data consisted of letters reporting sightings sent by
civilian observers directly to ATIC. Most of these direct communications
were dated subsequent to April 30, 1952, and are believed to be the result
of a suggestion by a popular magazine that future reports be directed to the
Air Technical Intelligence Center. As could be expected, a large number
of letters was received following this publicity.
A third type of data was that contained in questionnaire forms com-
pleted by the observer himself. A questionnaire form, developed during
the course of this study, was mailed by ATIC to a s_ele_cjted group of writers
of direct letters with the request that the form be completed and returned.
Approximately 1,000 responses were received by ATIC.
In general, the data were subjective, consisting of qualified estimates
of physical characteristics rather than of precise measurements. Further-
more, most of the reports were not reduced to written form immediately.
The time between sighting and report varied from one day to several years.
Both of these factors introduced an element of doubt concerning the validity
of the original data, and increased its subjectivity. This was intensified by
the recognized inability of the average individual to estimate speeds, dis-
tances, and sizes of objects in the air with any degree of accuracy. In
spite of these limitations, methods of statistical analysis of such reports in
sufficiently large groups are valid. The danger lies in the possibility of