Project Blue Book Special Report #14 – May 5, 1955

Background

Project Blue Book Special Report No. 14 was a massive statistical analysis undertaken by the U.S. Air Force and the Battelle Memorial Institute to study UFO sightings. This report is significant as it represents the largest such study ever undertaken, with a total of 3,200 cases analyzed by the time the report was completed in 1954. The goal was to make the UFO study more scientific, and the approach involved devising a standardized reporting form and analyzing the existing sighting reports based on about 30 report characteristics.

The analysts classified the cases into “knowns”, “unknowns”, and a third category of “insufficient information”. They further broke down knowns and unknowns into four categories of quality, from excellent to poor. Notably, for a case to be classified as an “unknown”, all four analysts had to agree, making the criterion quite stringent. Sightings were also analyzed based on six different characteristics—color, number, duration of observation, brightness, shape, and speed. These characteristics were then compared between knowns and unknowns to see if there was a statistically significant difference.

The main findings of the statistical analysis were as follows:

About 69% of the cases were judged as known or identified (38% were considered conclusively identified while 31% were still “doubtfully” explained), about 9% had insufficient information, and about 22% were deemed “unknown”.
In the known category, 86% of the knowns were aircraft, balloons, or had astronomical explanations. Only 1.5% of all cases were judged to be psychological or “crackpot” cases. A “miscellaneous” category comprised 8% of all cases and included possible hoaxes.
The higher the quality of the case, the more likely it was to be classified as unknown. 35% of the excellent cases were deemed unknowns, as opposed to only 18% of the poorest cases⁴.

Despite these findings, the summary section of the Battelle Institute’s final report declared it was “highly improbable that any of the reports of unidentified aerial objects … represent observations of technological developments outside the range of present-day knowledge.” This conclusion was criticized by some researchers, who noted that the conclusions of the analysts were usually at odds with their own statistical results, displayed in 240 charts, tables, graphs, and maps⁵.

When the Air Force made Special Report #14 public in October 1955, it claimed that the report scientifically proved that UFOs did not exist. However, critics noted that the report actually proved that the “unknowns” were distinctly different from the “knowns” at a very high statistical significance level. The Air Force also incorrectly claimed that only 3% of the cases studied were unknowns, instead of the actual 22%.

The results of the monumental study were echoed by a 1979 French GEPAN report, which stated that about a quarter of over 1,600 closely studied UFO cases defied explanation. When GEPAN’s successor SEPRA closed in 2004, 5,800 cases had been analyzed, and the percentage of inexplicable unknowns had dropped to about 14%.

Below, you will find a copy of the entire report, as archived by the CIA. This is the cleanest copy that I have seen, and complete.