CASCADE-SEA stands for computer supported curriculum analysis, design and evaluation for science education in Africa. It is the name of a computer program designed to help secondary level science teachers in southern Africa create exemplary paper-based lesson materials. Research conducted alongside the design and development of the CASCADE-SEA system explored how to shape performance support for teachers who are engaged in the complex task of developing exemplary lesson materials. After brief examination of the study's inception, the theoretical underpinnings are offered followed by a description of the research design. Thereafter, the software is briefly described before the findings are addressed. Design principles for constructing performance support of this nature are offered in the conclusion.