The choice of a lexical item for a verb can be completely determined by an object-specific script for a noun involved in the action, as in the table in the appendix. For example, the description of an open action will depend on the particular object that is being opened (a valve vs. an access panel); in this case, the object contains a named script for open, which determines the lexical item to choose. However, when such a script is not available, as is often true for low-level actions, or when the action is more widely applicable, a generic description of the action must be used.