Interdisciplinary working plays an important role in achieving impact outside academia. One barrier to interdisciplinary working is the lack of mechanisms to assess contributions from outside the primary discipline. Positioning our research in debates about knowledge translation, we analyse the ability of narrative cases to assess the interdisciplinary contribution of one academic discipline, Human Resource Development (HRD), to impact. We take the example of the cases used to assess impact in the UK's 2014 Research Excellence Framework evaluation (REF 2014). While the narrative cases revealed the complexity of knowledge translation and the role of HRD practice in it, their authorship by a single discipline imposed a linear structure and prevented interdisciplinary contributions from HRD academics from being recognised in the formal assessment. To facilitate the assessment of interdisciplinary contributions to academic impact, we propose remodelling the knowledge translation process as a net of cases rather than a single chain.