alternative facts - an appropriate expression for different-but-comparable data sets.
Appropriate: at one point, alternative facts told us with some accuracy that there were more slaves in the world today than ever before in history AND a smaller proportion of the human population is enslaved than ever before in history - because of population growth, these are both "facts", though somewhat generally expressed and needing further definition
NOT Appropriate: the crowd in a particular American city on a particular inauguration day was the largest ever AND the same crowd in the same American city on a particular inauguration day was NOT the largest ever - because of the specificity involved, these are NOT appropriately termed "alternative facts"
opinion - unverifiable expressions of personal/individual preference; often articulated in qualitative judgements like "good" or "bad," "best" or "worst," etc., but prone to reasonable and rapid dismissal without argument by others who merely disagree
T/truth - sometimes used interchangeably with "fact," but unlike "facts" T/truth is not always verifiable, but is usually worth an argument; often depends on some authority larger than the individual, like divine revelation or widely and strongly held communal ideals; a story that points to a larger truth can be deemed true, even if it is not factual (eg. "The Little Red Hen" "The Boy Who Cried Wolf" etc.). Since it is not always verifiable, and authorities may only be recognized by their particular communities, humility is needed and agreement should not necessarily be expected, but contradictory claims that cannot be reconciled through clarification should not BOTH be granted the status of "truth"
paradox - apparently contradictory truth claims that, upon closer examination, turn out NOT to be contradictory, for a variety of reasons (terms are used differently, different times, places and circumstances are being referred to, different perspectives or angles are being offered)