Referring expressions and other object descriptions should be maximal under the Local Brevity, No Unnecessary Components, and Lexical Preference preference rules; otherwise, they may lead hearers to infer unwanted conversational implicatures. These preference rules can be incorporated into a polynomial time generation algorithm, while some alternative formalizations of conversational impficature make the generation task NP-Hard. and avoid utterance (lb). Incorrect conversational implicatures may also arise from inappropriate attributive (informational) descriptions. .
