This article examines the pedagogical potential of a Web-based GIS application, Population Migration Web Service (PMWS), in which students can examine population geography in an interactive and exploratory manner. This article introduces PMWS, a tailored, unique Internet GIS application that provides functions for visualizing spatial interaction data. The easy-to-use interface of PMWS enables users to interactively and intuitively explore migration data in the form of flow maps and to use local data. The results of the usability survey indicated that pre-service teachers (n = 33) believe that PMWS represents an alternative GIS tool that overcomes the obstacles of desktop GIS in secondary education. (Contains 1 table, 5 figures, and 2 notes.)