Redesign of a query editor to support exploratory design tasks and foster language discovery

Platforms that combine interactive visual user interfaces with embedded code editing tools are commonly adopted in the fields of Big Data, Data Analytics, or Security Information and Event Management (SIEM). These dual interfaces allow intuitive and user-friendly access to different features and support all visual needs while providing high levels of customization and flexibility when needed. However, the high level of control enabled by the code-based interface often comes at the expense of usability and learnability. This thesis seeks to redesign a text-based code editor for a domain-specific query language embedded in a data monitoring visual interface to improve its overall usability and foster language discovery. The research follows a user-centered interaction design paradigm (IxD). A heuristic evaluation of the existing system using the Cognitive Dimensions of Notation framework (CDs) helped cross-check the insights from the initial user research and lead the design. The search for solutions also included a literature review on previous research to assess the suitability of mainstream Visual Programming Environments (VPEs) and coding support techniques in lowering skill barriers and improving usability. The identified pain points and insights from analysis of the existing mainstream approaches ruled out the implementation of any VPE, and a custom solution was designed. The proposed solution involved integrating a within-editor dual search engine that could support exploration and exploitation search task for an improved language usage, and a progressive evaluation system to better support exploratory design tasks, identified as the main activity performed by the users when building queries. The redesign was evaluated via a design walkthrough and an informal summative evaluation applying a revised version of the Technology Acceptance questionnaire. Results indicated high levels of perceived usefulness and perceived ease of use and captured possible future improvements