The Center for Technology in Learning at SRI International and the Concord Consortium are studying the impact on student learning of Web-based supplementary geoscience curriculum modules. Secondary- level students are participating in projects that address two neglected geoscience education standards: system knowledge and inquiry. Data sets are being developed with the combined expertise of geoscientists, science educators, researchers, and assessment specialists. Using an Earth System Science approach, students are interpreting and analyzing the data sets and visualizations, and communicating their findings. Design principles, specification templates, and prototype exemplars designed to improve geoscience knowledge and inquiry skills are being developed. These are serving as models for the geoscience education field and will lay the foundation for further resource development. Project assessments and design scenarios that supplement the curriculum modules are expanding the repertoire of resources available to geoscience educators.