The primary goal in editing is to prepare the surveys for data entry. Responses given in terms like "75-100%" or "most of the time" when asked for a single numeric response are typically caught and dealt with in the editing phase. Stray comments written in the margins of a survey may have important consequences on the interpretation of responses. Sometimes action items, such as "please call me about my bill" or "change my address", need to be immediately communicated back to your company.
There are some tasks best suited to humans, and some best left for computers to handle. Complicated skip patterns and instructions are often dealt with in later processing. Computer cleaning instructions can be objectively applied to all surveys based on a few simple rules.