For our task, the correctness of the prepositional phrase attachment is especially important for extracting accurate semantic role patterns (Gildea and Jurafsky, 2002 .
[ action Apply] [ theme Knowledge of [ concept IBM Ebusiness Middleware]] to [ purpose PLM Solutions] In this example, "Apply" is the "action" of the skill; "Knowledge of IBM E-business Middleware" is the "theme" of the skill, where the "concept" semantic role (IBM E-business Middleware) specifies the key component of the skill requirement and is the most important role for skill matching; "PLM Solutions" is the "purpose" of the skill.