This document discusses various aspects of data processing, including editing, coding, classification, and presentation of data. It describes two types of editing: field editing, which involves reviewing forms immediately after data collection; and central editing, which involves a thorough review of all forms once returned. Coding involves assigning symbols or numbers to responses to facilitate analysis. Classification involves arranging data into groups based on attributes or numerical characteristics. Common methods of presentation include tables and graphs. The goal of these data processing steps is to organize and reduce large datasets into a form that enables meaningful analysis.