While the ultimate goal of UFOlogy is to provide irrefutable evidence of the existence of visits to the earth by the residents of other planets, much of the time is spent in investigating purported UFO activity and discovering that there is a logical and earth-bound explanation for the sightings.
It is important to recognize that UFOlogy is not considered a valid science by the majority of the scientific community, there are a number of scientists with impeccable credentials in various fields of science that do engage in the investigation of UFOs.
At the same time, many dedicated UFOlogists hold expertise in fields other than science, such as in various forms of technology. While many UFOlogists are very slow to accept eyewitness reports and other types of sightings as possibly being of extra-terrestrial origin, there are many people involved with the studies who do not demand a great deal of evidence before accepting a sighting or encounter as valid.
This has made it easier for the general public, and the scientific community in general, to hold a low opinion of the study and pursuit of UFOlogy.