Practitioners in creative domains such as web design, data visualization, and software development face many challenges while trying to create novel solutions that satisfy the guidelines around practical constraints and quality considerations. My dissertation work addresses two of these challenges. First, guidelines may conflict with each other, creating a need for slow and time-consuming expert intervention. Second, guidelines may be hard to check programmatically, requiring experts to manually use multipage style guides that suffer from drawbacks related to searchability, navigation, conflict, and obsolescence. In my dissertation, I focus on exploring mixed-initiative methods as a solution to these challenges in two complex tasks: biological network visualization where guidelines may conflict, and web design where task requirements are hard to check programmatically.

For biological network visualization, I explore the use of crowdsourcing to scale up time-consuming manual layout tasks. To support the network-based collaboration required for crowdsourcing, I first implemented a system called GraphSpace. It fosters online collaboration by allowing users to store, organize, explore, lay out, and share networks on a web platform. I then used GraphSpace as the infrastructure to support a novel mixed-initiative crowd-algorithm approach for creating high-quality, biological meaningful network visualizations. I also designed and implemented Flud, a system that gamifies the graph visualization task and uses flow theory concepts to make algorithmically generated suggestions more readily accessible to non-expert crowds. Then, I proposed DeepLayout, a novel learning-based approach as an alternative to the non-machine learning-based method used in Flud. It has the ability to learn how to balance complex conflicting guidelines from a layout process. Finally, in the domain of web design, I present a real-world iterative deployment of a system called Critter. Critter augments traditional quality assurance techniques used in structured domains, such as checklists and expert feedback, using mixed-initiative interactions. I hope this dissertation can serve to accelerate research on leveraging the complementary strengths of humans and computers in the context of creative processes that are generally considered out of bounds for automated methods.