Out of the answers there I like AccuracyNormalized best.
That immediately conveys (to me at least) what it is and what its magnitude will be bounded by.
Or...if you were writing Java or Swift
NonNegativeMagnitudelessFractionalQuantity
The takeaway is words are mostly a leaky abstraction, imperfect model for math concepts.
But I guess if you're a clever programmer you could call it a ThielAccuracy, or ThielRatio
But I guess a number that's always between 0 and 1 is an integer reciprocal. But again that's probably getting too deep for this.
I guess another way is UnitIntervalPoint or ProperFraction
I guess in Java we don't have to choose
FractionalPartRatioForAccuracyNormalized hehehe
I suppose we could make up a word
bition, or bitum
anabit or cobit - analog bit (continuous on 0 to 1)
proratio - proper ratio
Making up a word seems easier than the rest because it's more concise. :)