PolitiFact ratings aren't scientific--or are they?

We stand bemused by PolitiFact's attempt to straddle the fence regarding its aggregated "Truth-O-Meter" ratings.

On the one hand, as PolitiFact Editor Angie Drobnic Holan told us a few weeks ago, "It’s important to note that we don’t do a random or scientific sample."

On the other hand, we have this eye-popping claim Holan sent out via email today (also published to the PolitiFact.com website):

Trump remains a unique figure in American politics and at PolitiFact. There’s no one we’ve fact-checked as many times who has been as consistently wrong. Out of 738 claims we’ve fact-checked as of this writing, more than 70% have been rated Mostly False, False or Pants on Fire. After four years of watching Trump campaign and govern, we see little to no increase in his use of true facts and evidence to support his arguments.

Even though it is supposedly important to note that PolitiFact doesn't do a random or scientific sample, Holan makes no mention of that important caveat in her email. Instead, she makes it appear to the reader as though Trump's "Truth-O-Meter" record offers a reasonable basis for judging whether Trump has increased "his use of true facts and evidence to support his arguments."

How would PolitiFact judge whether Trump was using more true facts to support his arguments other than by looking at unscientific fact checker ratings?

PolitiFact has made a pattern of this deception.

The occasional admission of non-random, unscientific story selection is perfunctory. It is a fig leaf.

PolitiFact wants readers to judge politicians based on its aggregated "Truth-O-Meter" ratings.

For some unknown reason, though maybe we can guess, the fact checkers think their collected ratings are pretty much accurate judges of character regardless of their departure from the scientific method. And that's why PolitiFact over its entire history has implicitly and explicitly encouraged readers to rely on its graphs and charts to judge politicians. And has steadfastly resisted the obligation to attach a disclaimer to those charts and graphs making the supposedly important point that the selection process is not random or scientific.

We call it an obligation because we view it as a requirement for journalists to avoid deliberately deceiving their audiences.

PolitiFact deceives its audience daily in this way without any visible repentance.