Operator

An operator performs a single, precisely defined task on the business data. Each operator is applied in exactly one step. Each operator has parameters which define its input and output in terms of the data on the conceptual level. There are two basic kinds of operators: those whose output is a concept and those that add an extra feature to their input concept. A few operators do not belong to either of these categories. Examples for tasks that operators perform are the replacement of missing values in the data that belongs to the input concept, or the creation of a new view on the data from the input concept, or the selection of important features from the input concept, etc.