PIGAS: an interactive statistical database management system
M. Wartelle, A. Kramar, P. Jan, Dov Kruger · Statistical and Scientific Database Management · 1983
PIGAS is an interactive statistical database management system whose main assets include logical data checking, data entry for meaningful variables only, three different types of missing value codes, non-rectangular data structure and user interfaces with BMDP, GLIM or specifically written FORTRAN programs.The structure of the PIGAS language is the same as one passes from one phase of a research study to another, whether it be data updating, checking or analysis, thus requiring only a minimum amount of initiation in its use. It is particularly appealing since data verification is completely specified through variable names as they appear on the questionnaire. Instructions given in how to fill in a questionnaire can thus be directly incorporated in the data checking process, thus ensuring a good quality data base.