High performance computing (HPC) has driven collaborative science discovery for decades. Exascale computing platforms, currently in the design stage, will be deployed around 2022. The next generation of supercomputers is expected to utilize radically different computational paradigms, necessitating fundamental changes in how the community of scientific users will make the most efficient use of these powerful machines. However, there have been few studies of how scientists work with exascale or close-to-exascale HPC systems. Time as a metaphor is so pervasive in the discussions and valuation of computing within the HPC community that it is worthy of close study. We utilize time as a lens to conduct an ethnographic study of scientists interacting with HPC systems. We build upon recent CSCW work to consider temporal rhythms and collective time within the HPC sociotechnical ecosystem and provide considerations for future system design.

Scientific data volumes have been growing exponentially. This has resulted in the need for new tools that enable users to operate on and analyze data. Cyber infrastructure tools, including workflow tools, that have been developed in the last few years has often fallen short if user needs and suffered from lack of wider adoption. User-centered Design (UCD) process has been used as an effective approach to develop usable software with high adoption rates. However, UCD has largely been applied for user-interfaces and there has been limited work in applying UCD to application program interfaces and cyber infrastructure tools. We use an adapted version of UCD that we refer to as Scientist-Centered Design (SCD) to engage with users in the design and development of Tigres, a workflow application programming interface. Tigres provides a simple set of programming templates (e.g., sequence, parallel, split, merge) that can be can used to compose and execute computational and data transformation pipelines. In this paper, we describe Tigres and discuss our experiences with the use of UCD for the initial development of Tigres. Our experience-to-date is that the UCD process not only resulted in better requirements gathering but also heavily influenced the architecture design and implementation details. User engagement during the development of tools such as Tigres is critical to ensure usability and increase adoption.

There has been much recent interest in the development of tools to foster remote collaboration and shared creative work. An open question is: what are the guidelines for this process? What are the key socio-technical preconditions required for a geographically distributed group to collaborate effectively on creative work, and are they different from the conditions of a decade or two ago? In an attempt to answer these questions, we conducted empirical studies of two seemingly very different online communities, both requiring effective collaboration and creative work: an international collaboration of astrophysicists studying supernovae to learn more about the expansion rate of the universe, and a group of children, ages 8-15, from different parts of the world, creating and sharing animated stories and video games on the Scratch online community developed at MIT. Both groups produced creative technical work jointly and were considered successful in their communities. Data included the analysis of thousands of lines from chat and comment logs over a period of several months, and interviews with community members. We discovered some surprising commonalities and some intriguing possibilities, and suggest guidelines for successful creative collaborations. Specifically, systems that support social creativity must facilitate sharing and play, and their design must consider the effects of repurposing, augmentation and behavior adaptation.

There is a growing need for distributed teams to analyze complex and dynamic data streams and make critical decisions under time pressure. Via a case study, we discuss potential guidelines for the design of software tools to facilitate such collaborative decision-making. We introduce the term context-linked to characterize systems where both task and context information are included in a shared space. We describe a novel, lightweight, context-linked event notification/virtual assistant system developed to aid a cross-cultural, geographically distributed team of astrophysicists to remotely maneuver a custom-built instrument under challenging operational conditions, where critical decisions must be made in as little as 45 seconds. The system has been in use since 2005 by a major international astrophysics collaboration. We describe the design and implementation of the event notification system and then present a case study, based on event log analysis and user interviews, of its effectiveness in substantially improving user performance during time-critical science tasks. Finally, we discuss the implications of context linking for supporting common ground in distributed teams.