<P> The Nursing Interventions Classification (NIC) is a care classification system which describes the activities that nurses perform as a part of the planning phase of the nursing process associated with the creation of a nursing care plan . </P> <P> The NIC provides a four level hierarchy whose first two levels consists of a list of 433 different interventions, each with a definition in general terms, and then the ground - level list of a variable number of specific activities a nurse could perform to complete the intervention . The second two levels form a taxonomy in which each intervention is grouped into 27 classes, and each class is grouped into 6 domains . </P>

How many classes are included in the second level of the nursing interventions classification model