There is no absence of evidence, not by a long shot. There are fewer written records in the traditional sense (books, letters, legal documents concerning things like transfer of property) but there is no shortage of inscriptions on various sorts of things, for example -- not to mention every other kind of historical evidence and, of course, the fact that some aspects of early medieval Western chronology can be cross-checked against contemporary sources in North Africa and the Middle East. We call it "the Dark Age" by comparison with, say, Late Antiquity, but even so, we have vastly more evidence about what happened in this age in Western Europe than we have about what happened in various ages of Antiquity all over the place, and no one thins those were made up.
As for the article you linked to, that kind of probabilistic approach sort of works for recent events. Applying it to things that happened a long time ago, where the presence or absence of evidence is correlated with a whole lot of other things, from court historians making shit up to cows tripping up over a lamp light and burning whole cities, is a pretty futile exercise.
As for the article you linked to, that kind of probabilistic approach sort of works for recent events. Applying it to things that happened a long time ago, where the presence or absence of evidence is correlated with a whole lot of other things, from court historians making shit up to cows tripping up over a lamp light and burning whole cities, is a pretty futile exercise.