I follow a (very) wide spectrum of accounts on Twitter and the following seemed true for the accounts I follow which scored highly likely to be bots:
- it's 50/50 accurate picking actual bots I know I follow
- the more simple the reading level, the higher it scored
- however, extremely heady accounts also score high
- the farther right/left the account goes seems to up the score a little
- accounts that quote authors frequently score very high, even if they're human behind them
- everything from Chinese state media scored higher than anything
- everything that was frequently highly critical of China scored extremely high
- most Trumpers and Antifa I follow had very low scores (but most are high-up/origin accounts)
- most news organizations from both sides scored middle range, including known propagandists and "reputable" organizations
- accounts from both sides of the COVID discussion were mostly low
Hard to say, but my best guess is "low effort" is the defining factor. Only exception is the pro/anti-Chinese stuff, which is definitely a mix of real people and bots.
I keep pretty good tabs on the accounts I follow and I think I'm pretty good at determining who is "a real person with real feelings saying real things they really think" and bots, and from this analysis, I have zero faith that this tool has any modicum of reliability in a research setting.
I think it's possibly accurate enough to say "yes, this is definitely a human", but totally fails to identify bots. Thus, any research that uses this tool as a measure of bot influence is way off, because there are way too many false positives. Which I guess is a good thing for anyone who wants to say, "look at all these people being suckered by all these bots!" which is pretty unscrupulous.
YMMV