Ufology is a pseudo-science. That means, those so-called experts in ufo phenomena are self-proclaimed experts in a field that fraudulently masquerades as a science. This may not be politically correct, and I am sure it will offend all the millions of people who believe in astrology, psychic surgery and that the world is flat.
First of all, there is no accredited university in the world that gives any degree in ufology. So, how does one become an expert? One merely reads all the crack-pot books that other ufologists have written and then buy some fancy gizmos at Radio Shack and set up your criteria. It always helps to have a limited amount of understanding of photography so that you can claim to "analyze" photographs. And if you are skilled at directing suggestible people into believing that the time they took a nap, they actually lost time from their life because of an alien abduction. If you are really good at it, you might even be able to produce false memories through auto-hypnosis!
You see, there is no scientific validity to the study of unidentified flying objects other than determining, when possible, what they are. To go at it with the express purpose of discovering "the truth" that these phenomena are extra-terrestrial is the opposite of science. It is closer to seeking for miraculous images in toast or wall discolorations.
You see, science is all about taking something that we can observe and making a thesis about it, a proposition. Then we formulate an experiment to test if our proposition is true. If the experiment fails, then we change the proposition. If the experiment succeeds we tell others so they can replicate the experiment. If the experiment cannot be replicated, for whatever reason, it fails. Go back to step 2. Re-formulate your thesis until you can get an experiment that succeeds every time.
Ufology is all about the theory and the search. But there is no experiment that can be replicated. So the theories remain untested. There are aliens with big heads at Roswell. There are reptiloids at Area 51. Nixon showed a friend of his the alien bodies. John Glen saw an unidentified flying object. These aren't evidence. These are unsupported theories, conjectures and anecdotes. No experiment, no science.
It doesn't matter if a ufologist takes samples, makes measurements, has pictures, analyzes soil or gets a book full of interviews, it isn't science. Until a skeptic can duplicate the same experiment as a true believer, it isn't science.