We designed, implemented and evaluated a new concept for direct manipulation of databases, called dynamic queries, that allowsuserstoformulatequerieswithgraphicalwidgets,such as sliders. By providing a graphical visualization of the database and search results, users can find trends and exceptions easily. Eighteen undergraduate chemistry students performedstatisticallysignificantlyfasterusingadynamicqueries interface compared to two interfaces both providing form fillin as input method, one with graphical visualization output and one with all-textual output. The interfaces were used to expore the periodic table of elements and search on their properties.