Modal-style operators in qualitative data analysis Ivo Düntsch and Günther Gediga   View Paper (PDF)   Return to Main-Track Regular Papers Abstract We explore the usage of the modal possibility operator (and its dual necessity operator) in qualitative data analysis, and show that it - quite literally - complements the derivation operator of formal concept analysis; we also propose a new generalization of the rough set approximation operators. As an example for the applicability of the concepts we investigate the Morse data set which has been frequently studied in multidimensional scaling procedures. DiSC'03 © 2003 Association for Computing Machinery