Universes could be determined by following through the skip patterns in the survey. For most users this abundance of data results in confusion. It is difficult to understand why there are eight variables labeled sex in the file or why there are several variables that identify whether or not the person is a parent or guardian. Most users are expecting only one variable for each concept, not two or more. This redesign effort is aimed at solving the problems of time and duplication on the SIPP public use data files.
Time is simplified by carrying all variables on the monthly records.
Data duplication is simplified by eliminating most if not all of the variables carried more than once per month. The third goal of this redesign is to reduce the total number of variables necessary and to impose a simple logical structure to the record layout. This paper will describe the record layout for a single month of data. The problems of time are largely solved by carrying all data at the monthly level. In order to eliminate duplicate data, the general principle followed here is to eliminate all unedited variables that also exist in edited form.