Truth Index: Point of Reference

Since starting the tracking of the PolitiFact Truth Index, I’ve often wrestled with baseline and relative reference numbers in trying to give it a relative measure. I often use the average PolitiFact Truth Index overall (for PolitiFact’s first 5,000 rulings, it was -13.4). In the charts I create I often point out the Half True indicator, which is zero. And of course, one can compare the truth average of one group against the other.

For 2012, I created something I called an “Insta-Chart” so for certain things I’d instantly have a PolitiFact Truth Index App type chart to which all I had to add was a title. This would also make most of my charts appear consistent. And of course, when you’re doing it by formula you want to test your formula to make sure it works. So I put a 1 in for all the Truth-o-Meter categories, and in doing so the thought occurred to me that this “across-the-board” Truth Index might be THE baseline.

If someone PolitiFact rated all the time had, for whatever reason, an equal number of statements in each of the Truth-o-Meter categories, their Truth Index would be a -25. This reflects the fact that the Truth Index is a weighted average. In that respect, I have made a big mistake in looking at the individual Truth Index in terms of the Truth-o-Meter categories, for example, when I say the Republicans, with a Truth Index of -23, were on average about half way between Half True and Mostly False.

Here is how the table would look (and how the weighting affects the averages) in terms of having 1 in each of the six Truth-o-Meter categories as the baseline “average”.

Truth Index	Means in "Truthfulness"	Equates to in Score
50	George Washington Wannabe	1 in every category except Half True, Mostly False or Pants on Fire)
25	Way above average	1 in every category except Mostly False or Pants on Fire)        .
0 (zero)	Above average	1 in every category except Pants on Fire
-25	AVERAGE	1 in every category
-50	Below average	1 in every category except True.
-75	Way below average	1 in every category except True and Mostly True

Instead the Republican average of -23 should be compared to the generic across the board Truth Index average of -25. This means the Republicans are about evenly divided among all the Truth-o-Meter categories. The Democrats, at a Truth Index average of just above zero, are evenly divided among the True through False categories "without" Pants on Fire.  So we have a measure which incorporates the weighting of the average.

I don’t know if this is how it should be presented, but it does provide a comparison, and I will be using this as a reference point in future postings.