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On March 26, ISCA’20 general co-chair José Duato and I announced that, due to the COVID-19 pandemic, the conference would switch from an in-person event in Valencia (Spain) to a purely virtual one. An intense two-month pivot followed, whose outcome was ISCA’s first-ever virtual conference. Attendance more than doubled with respect to any prior ISCA: 1,701 attendees from all over the world, of whom 57% were students and 68% were ACM or IEEE members.

Content and Format

ISCA’20 included a number of new features:

  • The main program featured an industry track session—a first for ISCA. The content of this session was selected via submission and review processes independent of the regular track. (This was planned months before the switch to virtual.)
  • Authors of papers accepted to the main program uploaded a twenty-minute presentation of their work ahead of the conference dates, and we made these recordings available a week in advance, along with the papers, so that attendees would be able to watch/read at their leisure.
  • Live presentations for each paper in the main program comprised a five-minute summary of the work, followed by ten minutes of Q&A. (Times for industry track papers were slightly shorter due to schedule constraints.) Attendees submitted questions either prior to or during the live session.
  • Attendees could upvote questions by others, which avoided repetition and gave session chairs one way to select what questions to ask speakers. Even after the live session, attendees and authors were able to continue interacting in writing through the Q&A interface.
  • The program featured a dozen live “mini panels,” each on a topic for which the program committee had received a good number of paper submissions. The intent was to attempt to reproduce “corridor talk,” with attendees able to submit questions and comments via the live Q&A interface.
  • The conference schedule was laid out to try to cater to all time zones: The “premium” slot 10am-Noon EDT (New York time) was convenient for many countries in both Asia and Europe; the follow-up slot (Noon-2:30pm EDT) would probably catch many Asian attendees sleeping; and the same was probably true for European attendees during the 8-10:30pm EDT slot. In any case, all live sessions were recorded and available for later viewing.

Workshops and tutorials took up three full days prior to the main program. While most workshops followed a format similar to the main program, organizers were given latitude to do their own thing, and some did introduce variations. The format for tutorials varied widely, from straight material delivery to fully interactive coding sessions.


We used three main technology platforms to support ISCA’20:

  • Whova. This platform was already familiar to many ISCA regulars. In its original form, it works as a support tool for physical conferences, allowing attendees to check the agenda, read about speakers and their presentations, participate in discussion boards, or exchange contact info with others. It allows organizers to engage attendees by making announcements, providing a support chat, running contests, etc. In the wake of the COVID-19 pandemic, however, Whova added support for both prerecorded videos as well as live streams. The idea of one familiar platform holding the conference together was very attractive, and the very few alternatives out there were often shrouded in mystery—e.g., sign up for a “tour” with a salesperson—, and/or they were just not good enough. (I expect, and hope, that this landscape will evolve rapidly.)
  • Zoom. By the time ISCA’20 went virtual, many academic and industry professionals were already familiar with Zoom, so this was a no-brainer for live event support. For a large conference like ISCA, however, regular Zoom calls were too freeform (e.g., subject to Zoom bombing, interruptions, etc.), so we opted for Zoom webinars, where a few “panelists” have video and audio connections, and “attendees” interact with panelists via a Q&A interface, and otherwise watch the event passively. With the exception of two tutorials which secured their own Zoom arrangement, all workshops, tutorials, and main program sessions were mapped across four Zoom webinar accounts.
  • Wistia. We needed a platform to host all recordings. The standard choices of YouTube, Vimeo, etc., don’t work in many parts of China. Wistia did work, although it wasn’t free (and neither was Whova nor Zoom).

In hindsight, we probably overspent a little in capacity for both Zoom (number of attendees in any one session) and Wistia (amount of video bandwidth served). However, the alternative of coming up short during the event was simply not a risk we were willing to take.


At the conclusion of the conference, we asked attendees to fill out a survey, and we received 133 responses (8% of attendees). For about 55% of respondents, this was their first ISCA, even though 88% of respondents had already attended another conference before. Responses came from 19 different countries; countries contributing 5% or higher responses were the United States (75), India (10), and the United Kingdom (7).

The first section of the survey asked for the attendee’s hindsight on what worked and what didn’t. Respondents were strongly supportive of the “flipped model”—i.e., prerecorded talks and Q&A-heavy live sessions—, although there were some vocal detractors of the Q&A-heavy format in the survey’s freeform section. Respondents were also enthusiastic about the recording of live sessions for later viewing, the mini panels, and the written Q&A setup (support for submitting questions in writing, both offline and live, and the ability to upvote other people’s questions). Respondents were less excited about the support for discussion boards, the ability to see attendee profiles, or the support to exchange contact information.

The second section asked attendees to imagine being physically present at a hybrid virtual-physical conference and to consider what features from the list above they would still value. We asked this question because this is an option that is being considered for ISCA’21, as a way to expand ISCA’s reach and at the same time provide the in-person experience. Respondents provided answers remarkably similar to the ones above for the virtual-only conference experience. This makes sense, as many of these features may serve to enhance not only virtual but also in-person participation—e.g., the ability to submit questions in writing rather than having to line up at the microphone.

The third section of the survey asked about the industry track session and its multiple characteristics, from handling submissions separately to labeling the papers as “industry track” or holding the presentations in a distinct session. Respondents were very enthusiastic about all the aspects, essentially asking for a repeat next year.

Finally, attendees were given the opportunity to provide open feedback. A lot of the comments reinforced the level of enthusiasm (or lack thereof) for the different features asked about earlier in the survey. Two themes emerged that transcended the earlier questions:

  • First, that continuing to support virtual attendance moving forward is highly desirable, even if the conference is also hosted physically. Many respondents felt that virtual attendance makes the conference much more inclusive. We agree that supporting a hybrid format is very attractive; however, we would expect the complexity and cost of supporting virtual attendance to be higher in a hybrid scenario (for example, recording all live events and posting them shortly afterward would require dedicated equipment and staff).
  • Second, that Whova was not quite ready for prime time for handling virtual events (particularly their somewhat clunky web interface vs the more mature smartphone one), and that perhaps a leaner platform that focused on the more desirable features while giving up on the less popular ones would be preferable. Some respondents noted that, although Whova’s “virtual socialization” mechanisms weren’t really all that effective, ISCA should continue to experiment on this front. (On the organizers’ side of things, although Whova was overall very helpful in keeping everything organized, we were frustrated with some of its features or lack thereof. Most notably, the fact that Whova’s Q&A interface did not update clients in real time forced us to provide two different Q&A interfaces: Whova’s for offline communication and Zoom for live, real-time interaction.)

Multiple people also offered a piece of advice to future virtual attendees: Block your calendar almost as if you are actually traveling to the physical conference, or else be prepared to drown in a multitasking struggle between the virtual conference and your physical world.

 About the Author: José F. Martínez is Professor of Electrical and Computer Engineering at Cornell University, and a member of the SIGARCH Board of Directors. He was general co-chair of ISCA’20 with José Duato, Professor of Computer Science at the Universidad Politécnica de Valencia.

Disclaimer: These posts are written by individual contributors to share their thoughts on the Computer Architecture Today blog for the benefit of the community. Any views or opinions represented in this blog are personal, belong solely to the blog author and do not represent those of ACM SIGARCH or its parent organization, ACM.