It is essential for the search engine to correctly annotate the query structure, and the quality of these query annotations has been shown to be a crucial first step towards the development of reliable and robust query processing, representation and understanding algorithms (Barr et al., 2008;Guo et al., 2008;Guo et al., 2009;Manshadi and Li, 2009;Li, 2010).
in current query annotation systems, even sentence-like queries are often hard to parse and annotate, as they are prone to contain misspellings and idiosyncratic grammatical structures.