As research becomes increasingly interdisciplinary, the unique expertise of researchers in the field of geographic information science (GIScience) becomes harder to distinguish from that of scientists in other domains. What makes a GIScientist different from a biologist, economist, physicist, or epidemiologist, for example, who happen to be developing innovative new techniques for handling or analyzing geographic information in their specific domain? This talk critically examines the role of some established research topics in GIScience, and provides a reasoned perspective on what topics GIScience might claim to constitute its unique area of expertise.