CONTEXT DEPENDENCE
l The interpretation of most expressions depends on the context in
which they are used
– Studying the semantics & pragmatics of context dependence a crucial
aspect of linguistics
l Developing methods for interpreting context dependent
expressions useful in many applications
– Information extraction: recognize which expressions are mentions of
the same object
– Multimodal interfaces: recognize which objects  in the visual scene
are being referred to
l We focus here on dependence of nominal expressions on context
introduced LINGUISTICALLY, for which I’ll use the term
ANAPHORA