85 COLLABORATIVE DESIGN REASONING IN A LARGE INTERDISCIPLINARY LEARNING TOOL DESIGN PROJECT Feiya Luo, Pavlo “Pasha” Antonenko, Natercia Valle, Emily Sessa, Gordon Burleigh, Lorena Endara, Stuart McDaniel, Sarah Carey, & E. Christine Davis, University of Florida This design case discusses the complex collaborative design reasoning processes involved in developing an online in- teractive learning tool for learners of all ages to explore and understand the role of fagellate plants in our society. The learning tool consists of a main website (the Voyager) and an interactive, dynamic map of the evolutionary relationships between thousands of fagellate plant species (the custom- ized OneZoom web application). The design and develop- ment of this innovative learning tool required expertise in collaborative design, design reasoning, project management, theories of learning and instructional strategies, software development, and web usability. Collaboration platforms used by the project team involved GitHub and Slack. Domain knowledge needed to complete the project included botany (fagellate plants), web programming (Python and JavaScript), and database management (MySQL). The project included a team of international experts who negotiated design strategies and solutions over the course of a year and produced and improved prototypes until converging on the fnal product. This article explains the challenges faced during these processes and presents solutions and lessons learned from this experience. Feiya Luo is a Ph.D. candidate in Educational Technology at the University of Florida. Her research interests include using innovative technologies in integrated STEM. Pavlo “Pasha” Antonenko is an Associate Professor in Educational Technology at the University of Florida. Natercia Valle is a Ph.D. candidate in Educational Technology at the University of Florida. Emily Sessa is an Associate Professor in Biology at the University of Florida. Gordon Burleigh is an Associate Professor in Biology at the University of Florida. Lorena Endara is a Post-Doctoral researcher in Biology at the University of Florida. Stuart McDaniel is an Associate Professor in Biology at the University of Florida. Sarah Carey is a Ph.D. candidate in Biology at the University of Florida. E. Christine Davis is a Senior Lecturer in Biology at the University of Florida. INTRODUCTION The design case discussed here represents the work of a large team of interdisciplinary scholars, designers, and software development consultants aimed at creating an innovative online technology that underscores the role of fagellate plants in our society. For the frst 300 million years following plants’ invasion of land, Earth’s terrestrial fora consisted entirely of fagellate plants. These include the bryophytes, lycophytes, ferns, and gymnosperms, and today, these lineages comprise approximately 30,000 species. During the evolution of these groups, numerous botanical innovations evolved that defne plant biodiversity today. Stomata, vascular tissue, roots and leaves, lignifed stems with secondary growth, and seeds all evolved frst in fagel- late plant ancestors. These plants, therefore, hold the keys to understanding early evolution of these critical features. The fagellate plants not only provide a window to innovations of the past, but are represented by vibrant, speciating lineages that contribute substantially to modern global ecology, particularly via contributions to global carbon and nitrogen cycles (Voogt et al., 2015). Copyright © 2020 by the International Journal of Designs for Learning, a publication of the Association of Educational Communications and Technology. (AECT). Permission to make digital or hard copies of portions of this work for personal or classroom use is granted without fee provided that the copies are not made or distributed for proft or commercial advantage and that copies bear this notice and the full citation on the frst page in print or the frst screen in digital media. Copyrights for components of this work owned by others than IJDL or AECT must be honored. Abstracting with credit is permitted. https://doi.org/10.14434/ijdl.v11i1.25633 2020 | Volume 11, Issue 1 | Pages 85-97