Together They Stand: Interpreting Not-At-Issue Content.

Potts unified the account of appositives, parentheticals, expressives, and honorifics as 'Not- At-Issue' (NAI) content, treating them as a natural class semantically in behaving like root (unembedded) structures, typically expressing speaker commitments, and being interpreted independently of At-Issue content. We propose that NAI content expresses a complete speech act distinct from the speech act of the containing utterance. The speech act hypothesis leads us to expect the semantic properties Potts established. We present experimental confirmation of two intuitive observations made by Potts: first that speech act adverbs should be acceptable as NAI content, supporting the speech act hypothesis; and second, that when two speech acts are expressed as successive sentences, the comprehender assumes they are related by some discourse coherence relation, whereas an NAI speech act need not bear a restrictive discourse coherence relation to its containing utterance, though overall sentences containing relevant content are rated more acceptable than those that do not. The speech act hypothesis accounts for these effects, and further accounts for why judgments of syntactic complexity or evaluations of whether or not a statement is true interact with the at-issue status of the material being judged or evaluated.