Todate visualization has not been extensively harnessed in knowledge discovery in databases (KDD). In this paper, we show that a multidimensional visualization (MDV) technique can be usedsynergisticallywith a machinelearningprogram like C4.5 to uncovernew knowledge. Usedtogether, the two approachesspanthe KDD spectrumbetween completeautomationon onehandandfully manualon the other. We introduceMDV, its implementationin atool namedWinViz, andshowhow WinViz supports the varioustasksin KDD.