I don't know as a Prepositioned Epistemic Hedge

The present article reports on a study of a previously underexamined type of I don't know in everyday talk. The targets were all in first position and were syntactically complete utterances that were prepositioned or preliminary to a next thing within a turn. A core of 32 instances was drawn from a much larger collection of I don't knows taken from New Zealand, British, and American English corpora. The target I don't knows were preliminary to two broad categories of actions—first assessments and approximations. The findings suggest the target I don't knows function as a prepositioned hedge—a forward-looking stance marker displaying that the speaker is not fully committed to what follows in their turn of talk.