Evaluation-First Design for Data Visualization Interfaces

Existing frameworks in visualization and HCI emphasize iteration, data grounding, and stakeholder needs; however, they have not fully explored how evaluation might persist across phases, adapt to compressed timelines, and aid stakeholder engagement and elicitation. Building on prior frameworks, we introduce Evaluation-first design EvalOps that centers evaluation as a material component in the design process, emphasizing tighter feedback loops, co-evaluation with stakeholders, malleable forms of evaluation, and goals-to-metrics grounding. We illustrate how EvalOps shapes design outcomes through two case studies of data-visualization and LLM-enabled reasoning tools, demonstrating how evaluation-driven design facilitates alignment and trust, uncovers opportunities earlier, and supports cohesiveness under rapidly changing constraints. We contrast EvalOps with current visualization design methodologies and discuss opportunities for expanding evaluation-centered framings to other active areas of design research.