There is a controversial discussion on the role of transparency in open data contests. Existing designs of open data contests adopt transparency in different ways and report positive and negative implications for the innovation productivity of the contest contributors. This paper studies the role of transparency as an essential socio-technical design principle of open data contest platforms. It proposes two design features of transparency, namely performance transparency and solution transparency that allow the crowd to develop novel open data applications by integrating entrepreneurial experimentation with re-use for innovation. Adopting a design science method, we develop and test an open data contest platform design that jointly affords performance and solution transparency. Our pilot study of an open data mash-up hackathon provides evidence that these transparency features trigger both independent path creation and re-use for innovation. The result also shows mere copying will not result in good performance. Key Words: Performance transparency, Solution transparency, Technology Similarity, Code Reuse, Path Creation, Open Data Contests