Trade-offs in assessment and feedback design: a trilemma-based model

Assessment and feedback design is expected to satisfy an expanding range of educational, institutional and technological demands. Emerging technologies, particularly generative artificial intelligence, have intensified longstanding tensions around what assessment should achieve and what evidence can support credible judgements of learning. Educators are asked to design assessment that is authentic, inclusive, feedback-rich, defensible, scalable and sustainable, yet these aspirations cannot always be maximised simultaneously. Existing assessment and feedback frameworks provide valuable guidance about the characteristics of high-quality practice but offer limited support for making design decisions when legitimate educational priorities compete. This paper proposes the Dual Trilemma Framework as a conceptual lens for navigating these competing demands. The framework comprises an assessment trilemma of authenticity, observability and feasibility, and a feedback trilemma of usability, sources and sustainability. It positions assessment and feedback design as a process of making explicit and defensible trade-offs among competing educational priorities. These trade-offs can be distributed across coherent assessment systems, allowing different activities to make complementary contributions over time. The Dual Trilemma Framework provides educators with a shared conceptual language for making transparent, defensible and contextually appropriate assessment and feedback design decisions while complementing, rather than replacing, existing assessment and feedback frameworks.