As geographic information systems (GIS) are increasingly implemented in K–12 classrooms, the risk becomes one of teaching “buttonlogy” or simply how to point and click to complete certain functions. Through the development of a geospatial concept lexicon and corresponding geospatial task ontology along with simple concept-based tasks completed by students in different grade levels, this research has illuminated grade-related differences in geospatial concept recognition and understanding. In these experiments, simple paper and pencil tasks were given to 6th grade, high school, and undergraduate students to provide insight into different levels of concept understanding, specifically in terms of grade-related abilities to comprehend descriptions of spatial relationships. Results indicate significant differences in geospatial concept recognition, understanding, and use among the grade-based participants tested during the course of the project. These results can be used to inform the development of a “Minimal GIS” in which a pedagogic goal of grade-appropriate concept understanding becomes the driving force behind the GIS, suggesting the structure of an effective support system for spatial thinking.