Improvements in citizen participation are among the core benefits often attributed to the publication of Open Government Data (OGD). However, our specific understanding of the range of added value that OGD can bring to citizen participation projects remains limited. In this paper, we employed the Repertory Grid Technique with eight practitioners to gather examples of citizen participation projects utilizing OGD and to understand how OGD adds value to these projects. Through this approach, we identified ten qualities associated with higher OGD added-value and conceptualized six archetypes that describe how OGD can be integrated into citizen participation projects. Our findings enhance existing conceptualizations of OGD use in citizen participation and provide practitioners with a comprehensive and detailed overview of potential OGD applications and key qualities to consider for improving their participation projects.