Relatório Especial 14 em números: 3.201 relatos, 2.199 fenômenos e 434 desconhecidos entre 1947 e 1952

translation and transcription from reports to punched cards, indicated that there would be relatively few specific variables or factors that would yield meaningful correlation studies. Either the original data were too subjective, or the incompleteness of the original reports would seriously reduce the sample of a specific variable. Preliminary tabulations of various sortings substantiated the impossibility of deriving statistical results from certain variables, such as movement of the observer during the sighting, sound, shape parameter, size, angular velocity and acceleration, appearance and disappearance bearing, initial and final elevation, altitude, and orientation of the object. The statistically usable variables presented in this study include the date, time, location, duration, reliability, and method of observation of the sighting, and the physical attributes of number, color, speed, shape, light brightness, and identification of the objects sighted. The presentation of frequency and percentage distributions of any of the variables must be interpreted in the light of the sample of incidents represented. For example, the analysis of the reported colors of the objects sighted, based on ALL SIGHTINGS, could lead to misrepresentation of the distribution of the reported color of the objects, because of the multiplicity of reports on some of the phenomena. On the other hand, the percentage distribution of the light brightness reported by each observer is more likely to be correct than a distribution based on one report for each phenomenon. To assure that the most nearly correct presentation was made, and to avoid the possibility of failure to uncover any pattern or trend inherent in the data, the variables were studied on five different bases or samples. These samples, and their numerical relation to each other, were as follows: ALL SIGHTINGS (all reports) 3,201 cards UNIT SIGHTINGS, all observers 2,554 cards UNIT SIGHTINGS, single observer 2,232 cards UNIT SIGHTINGS, multiple observers 322 cards OBJECT SIGHTINGS 2,199 cards The preliminary tabulations indicated that the samples based on UNIT SIGHTINGS, single observer, and UNIT SIGHTINGS, multiple observers, would not add materially to this study. Accordingly, although the frequency distributions were recorded and are available for study, they are not presented in this report. The bases of ALL SIGHTINGS, UNIT SIGHTINGS (referring to all observers), and OBJECT SIGHTINGS are presented in Appendix A as Tables A1 through A240. A critical study of these tabulations reveals that there is no apparent change in the distribution of any variable from one basis to another, and that no marked patterns or trends exist in any sample.

Graphical Presentation Graphical representation of the important information contained in the tables is presented in Figures 1 through 38. These figures present the distributions of the important variables only by the total number of cases in each identification category, since no significant differences were found between the distributions of "Certain" and "Doubtful" identifications of objects with respect to the variables. A chronological study of these figures will afford a broad picture of the tabulated information, without the necessity of a detailed study of the tables. A critical examination of the figures will show that no trends, patterns, or correlations are to be found, with the exception of Figures 18 through 30. The apparent similarity of the distributions shown by these mirror graphs, Figures 18 through 23, was tested by statistical methods which showed that there was a low probability that the distributions of the KNOWNS and UNKNOWNS by these characteristics were the same. These tests and their interpretation are discussed in the following section. For purposes of this study, the strategic areas, shown in Figures 32 through 38, and Tables A223 through A240, Appendix A, were designated on the basis of concentration of reports of OBJECT SIGHTINGS in an area. No other interpretation of the tables or remaining charts was deemed necessary. Advanced Study of the Data It was recognized that the lack of any patterns or trends, as shown by the tabulations and graphs, provided an insecure basis for drawing definite conclusions. Accordingly, shortly before the sorting and tabulation program was concluded, a program of study of the data was developed to utilize statistical and other mathematical methods, which could lead to a more concrete interpretation of the problem. Position of the Sun Relative to the Observer The first thing that was done was to calculate the angle of elevation of the sun above the horizon and its bearing from true north as seen by the observer at the time of each sighting. With this information, it could then be determined whether there was a possibility that the reported object could have been illuminated by light from the sun. In addition, it could be determined whether an object could be a mock sun (sun dog) or whether there was a possibility of specular reflection from an aircraft at the position of the object, which would give the appearance of a "flying disc". A program of computation was set up and carried out to obtain the angle of elevation and the bearing of the sun for each sighting. All information needed for this calculation was available on the deck of IBM cards.

FIGURE 1 FREQUENCY OF SIGHTINGS BY YEAR FOR OBJECT, UNIT, AND ALL SIGHTINGS. Object sightings 2199 = 100%: 1947, 79 = 3.6%; 1948, 143 = 6.5%; 1949, 186 = 8.5%; 1950, 169 = 7.7%; 1951, 121 = 5.5%; 1952, 1501 = 68.3%. Unit sightings 2554 = 100%: 1947, 97 = 3.8%; 1948, 153 = 6.0%; 1949, 236 = 9.2%; 1950, 209 = 8.2%; 1951, 137 = 5.4%; 1952, 1722 = 67.4%. All sightings 3201 = 100%: 1947, 117 = 3.7%; 1948, 205 = 6.4%; 1949, 395 = 12.3%; 1950, 306 = 9.6%; 1951, 160 = 5.0%; 1952, 2018 = 63.0%. A-7479

FIGURE 2 DISTRIBUTION OF EVALUATIONS OF OBJECT, UNIT, AND ALL SIGHTINGS FOR ALL YEARS. Object sightings 2199 = 100%: Unknown 434 = 19.7%; Astronomical 479 = 21.8%; Aircraft 474 = 21.5%; Balloon 339 = 15.4%; Insuf. info. 240 = 10.9%; Other 233 = 10.3%. Unit sightings 2554 = 100%: Unknown 497 = 19.5%; Astronomical 639 = 25.0%; Aircraft 527 = 20.6%; Balloon 379 = 14.8%; Insuf. info. 261 = 10.2%; Other 251 = 9.9%. All sightings 3201 = 100%: Unknown 689 = 21.5%; Astronomical 817 = 25.5%; Aircraft 642 = 20.1%; Balloon 450 = 14.0%; Insuf. info. 298 = 9.3%; Other 305 = 9.6%. A-7480

FIGURE 7 FREQUENCY OF OBJECT SIGHTINGS AND UNKNOWN OBJECT EVALUATIONS BY MONTHS, 1947-1952. Vertical axis: Number of Object Sightings (broken scale above 60, up to 500). Curves: All object sightings; Unknown object sightings. Horizontal axis: months J F M A M J J A S O N D, 1947 to 1952. C-7485

FIGURE 8 DISTRIBUTION OF OBJECT SIGHTINGS BY SIGHTING RELIABILITY GROUPS WITH EVALUATION DISTRIBUTIONS FOR EACH GROUP. Center: 2199 = 100%; Excellent 213 = 9.7%; Good 757 = 34.5%; Doubtful 794 = 36.0%; Poor 435 = 19.8%. Excellent, 213 = 100%: Unknown 71 = 33.3%; Astronomical 52 = 24.4%; Aircraft 41 = 19.2%; Balloon 25 = 11.8%; Other 15 = 7.0%; Insuf. info. 9 = 4.2%. Good, 757 = 100%: Unknown 188 = 24.8%; Astronomical 174 = 23.0%; Aircraft 166 = 22.0%; Balloon 127 = 16.8%; Other 75 = 9.9%; Insuf. info. 27 = 3.6%. Doubtful, 794 = 100%: Unknown 103 = 13.0%; Astronomical 154 = 19.4%; Aircraft 198 = 24.9%; Balloon 131 = 16.5%; Insuf. info. 111 = 14.0%; Other 97 = 12.2%. Poor, 435 = 100%: Unknown 72 = 16.6%; Astronomical 99 = 22.8%; Aircraft 69 = 15.9%; Balloon 56 = 12.9%; Insuf. info. 93 = 21.4%; Other 46 = 10.6%. A-7486

FIGURE 32 DISTRIBUTION OF OBJECT SIGHTINGS BY EVALUATION FOR THE TWELVE REGIONAL AREAS OF THE UNITED STATES, WITH THE STRATEGIC AREAS LOCATED (STRATEGIC AREAS WERE DETERMINED ON THE BASIS OF CONCENTRATION OF OBJECT SIGHTINGS). Map labels: CANADA; MEXICO; North Farwest; Central Farwest; South Farwest; Northwest; Central West; Southwest; North Midwest; Central Midwest; South Midwest; North East; Central East; South East. [pie-chart figures in each region too small to transcribe reliably]