4. The method of claim 1 , wherein a key phrase is tied-to-content when the key phrase is semantically unique and is frequently associated with a specific content.
4. The method of claim 1 , wherein a key phrase is tied-to-content when the key phrase is semantically unique and is frequently associated with a specific content. 5. The method of claim 4 , wherein a key phrase is representative-of-content when the key phrase is associated with other content.