Grounding Meaning: Composition versus Abstraction

I recently read an interesting paper, How Is Meaning Grounded in Dictionary Definitions? The abstract follows:
Meaning cannot be based on dictionary definitions all the way down: at some point the circularity of definitions must be broken in some way, by grounding the meanings of certain words in sensorimotor categories learned from experience or shaped by [...]

Lexicons versus Corpora for Measures of Semantic Distance

Measures of semantic distance (or, inversely, semantic relatedness) have many applications in Computational Linguistics. There are three basic approaches to measuring semantic distance: lexicon-based algorithms, corpus-based algorithms, and hybrids. In an otherwise excellent paper on lexicon-based measures, Budanitsky and Hirst criticize corpus-based measures. I discuss their criticisms here.