Comparison of IFOs to UFOs by characteristics

A key study of BBSR was to statistically compare IFOs and UFOs by six characteristics: color, number of objects, shape, duration of observations, speed, and light brightness. If there were no significant differences, the two classes were probably the same, the UFOs then representing merely a failure to properly identify prosaic phenomena that could already account for the IFOs. On the other hand, if the differences were statistically significant, this would suggest IFOs and UFOs were indeed distinctly different phenomena.

In the initial results, all characteristics except brightness tested significant at less or much less than 1% (brightness was greater than 5%). By removing «astronomical» sightings from the «knowns» and redoing the test, just two categories, number and speed, were significant at less than 1%, the remainder having results between 3% and 5%. This indicated that there was a statistically significant difference between the characteristics ascribed to UFOs and IFOs, but perhaps not as significant as the initial results suggested. For two characteristics, brightness and speed, the significance actually increased with the revised test.