All tree-building methods discard some data, and therefore such data are "uninformative" for building trees using that method. For instance, in parsimony methods only characters whose number of steps can vary on trees are informative; autapomorphic and invariant characters are uninformative (these can be determined by inspection of the data). However, in UPGMA autapomorphic characters are informative. (cf. informative).

not tending to inform or clarify; "an unenlightening comment"

not informative or enlightening