Scheduling a Global UIST 2021

Frederik Brudy
Published in
7 min readJul 1, 2021


One of the biggest challenges in organizing a virtual international conference is deciding how to create a schedule that works for as many people as possible across many time zones. In this post, we will attempt to summarize the decisions that we’ve made for 2021 and the reasoning behind those decisions.

In case you don’t have time to read the details, here are the key points:

  • UIST will be held from October 10–14, with some variation depending on your time zone.
  • We are adopting a 24-hour schedule with three 4-hour slots each day
  • Authors will present their Paper twice in two different slots over the course of the conference.
  • Pre-prints of accepted Papers will be made available to registered attendees as early as August 11. Attendees may begin discussing papers on Discord as soon as they are released, and authors are encouraged to engage in the conversation as early as possible.
  • Paper presentations are held in Zoom, with Discord as a backchannel. Note that both presenters and audience members attend via Zoom, and there will not be a separate livestream or other technical separation between the two groups.
  • Each Paper gets 15 minutes, with ~7 minutes for a pre-recorded talk and the rest for live discussion / Q&A.
  • Authors are encouraged to pose discussion points to the audience either as part of their talk or before their talk on Discord.


UIST 2021 will be held virtually from Sunday, October 10 through Thursday, October 14. The Doctoral Consortium will take place on the first day (October 10), and the main technical program will take the remainder of the time. Inspired in part by the CHI conference, we have chosen to use a 24-hour format to give our global audience the opportunity to attend during “acceptable hours,” which we have loosely defined as not after 11pm and not before 7am. We acknowledge that the understanding of what constitutes “acceptable” differs for every attendee around the globe, but we hope that we have built in enough flexibility that there are reasonable options for most people. In addition, we will release pre-prints of the accepted papers in mid-August and authors’ recorded talks will be made available to registered attendees around the start of the conference.

In the following sections we explain our global schedule, our considerations in creating it, and our expectations for paper presenters.

The 24 Hour Schedule In Detail

UIST will host an engaging technical program of Papers, Demos, Posters, and Doctoral Consortium. In addition, we will also have keynotes, UIST Visions, Lightning talks, and a variety of social events. More details about the latter will be provided by the Social Events Chairs in a subsequent blog post.

UIST will be run as a multi-track conference over the course of four days. Day 1 is dedicated to the Doctoral Consortium (October 10). The main conference will start on Monday, October 11 at 4pm PDT and conclude with a final paper session starting on Thursday, October 14 at 8am PDT. For our friends in Europe (CEST time zone), the first session starts on Tuesday, October 12 at 1am and the last slot starts on Thursday, October 14 at 5pm. In Japan, the first session starts on Tuesday, October 12 at 8am and the last session starts on Friday, October 15 at midnight.

Each piece of content in the technical program, which includes papers, demos, and posters, will be presented twice over the course of the three main conference days. A paper’s two presentations might be assigned throughout the entire conference, however presenters will be able to choose two out of the three day-slots in which to present. This will allow authors to present within hours they find reasonable and enable attendees in most time zones to experience all the content in at least one of its presentation slots.

Each 4-hour slot will start with 1-hour dedicated to plenary content like Keynotes, the Townhall, Visions and other content that is of interest to the entire UIST community. This is followed by a 2-hour block dedicated to Papers.

Paper sessions will be held via Zoom webinars, similar to how they were for UIST 2020. We will assign each session to a named Discord “room” (e.g., Indigo, Fuchsia, Saffron), with an accompanying Zoom link. Each 2-hour session starts with a few of the new UIST Lightning Talks, which are 60 second introductions by early-career researchers and professionals (details forthcoming). Following that, each paper will be allocated 15 minutes, which starts with the playback of a pre-recorded presentation followed by a live discussion moderated by the session chair.

Each slot closes with a one hour Demo / Poster session. Details about the schedule for the demo and poster sessions are forthcoming.

This figure shows how the UIST’21 schedule is split across different time zones. Each day is split into three slots where content will be presented. Each slot starts with 1 hour dedicated for plenary content, such as keynotes, Visions, Townhall, etc. It is then followed by a 2–hour block of Paper presentations, and a 1–hour block for Demos and Posters. Each timezone in this figure overlaps with at least two slots each day.
UIST 2021 will be run as a 24-hour schedule, over the course of four days. Each piece of content in the technical program will be repeated twice.

This year, pre-print papers will become available to conference registrants much earlier, as soon as August 11, 2021. This is just one week after the camera-ready deadline, and approximately two months earlier than past years. There will be channels for each paper on Discord available to registered attendees from the time that pre-prints are made available. Through this we hope that attendees will engage earlier with the content and contribute to a lively conversation before and during the conference.

Why the 24 Hour Schedule?

Being an entirely remote conference, there are several considerations that we needed to take into account in developing our schedule.

UIST attendance in the years 2014–2020

First, one of the most important considerations was the time zone within which attendees might be located. To understand this better, we looked at UIST attendance over the past few years. Historically UIST has had strong attendance from the USA & Canada, Europe (Central, West, and South), and Japan & South Korea. Attendees from other countries made up ~1–2% of all attendees over the period we examined. UIST 2020 was the first fully virtual conference, and we looked carefully at its attendee list to see if there were any major shifts that we should accommodate, but it turned out that the global distribution of attendees was very similar to previous years (see the table below). Because of this consistent distribution of attendees across the world over several years, we chose to focus on these three global zones. As mentioned earlier, our goal is that participation should be possible within “reasonable hours of the day” in each of these time zones. While this differs for every person, we aim to enable full participation not before 7am and not past 11pm.

UIST attendance in the years 2014–2020

Second, we considered how many hours per day we can reasonably expect attendees to participate. We expect many attendees will have to juggle conference attendance with everyday work, family time, and other tasks unrelated to the conference. We think it is important to be mindful of people’s schedules and enable people to attend the conference without committing a full day of exclusive attention.

Lastly, we considered whether to continue the multi-track model of previous UIST conferences or attempt to return to a single track model like UIST conferences of old. Initially, we thought this latter option might be possible given the increased flexibility of a virtual conference. Ultimately however, we found that accommodating the extensive amount of diverse content that will be presented at UIST within our “reasonable hours” guideline was not easily possible. After all, we expect 95 papers, plus posters, demos, plenary content, and more…

For these reasons we decided to adopt a schedule that focuses on the previously mentioned main global zones within a multi-track technical programme. Most technical content will be repeated twice over the course of the conference and available on demand.

Expectations of Paper Authors

Authors of accepted Papers will need to prepare the following content for their presentations before the conference. Note, this applies for Papers accepted to the conference. Other venues will have different requirements and the details will be communicated by the Chairs. This information will also be included in messages to authors and posted to the UIST web site.

Content to be provided in advance of the conference:

  • Paper and (optional) video figure. Pre-prints will be released very soon after acceptance, as early as August 11, 2021.
  • 30 second Video Preview. Submission deadline August 11, 2021 at 5pm PDT. Video Previews will be released shortly after their submission.
  • Pre-recorded talk length. Minimum length 5 minutes, maximum 10 minutes. Presenters can decide how long their talk should be and the rest of their presentation-time (15 minutes) will be filled with live discussion / Q&A. We encourage authors to keep their talk around the 7 minute mark to allow a lot of time for discussion.
  • Pre-recorded talk submission deadline. The early submission deadline is August 11 at 5pm PDT and the late submission deadline is on September 15 at 5pm PDT. Submitting on the early deadline will result in the video being added to the ACM Digital Library as well as YouTube. Submission on the late deadline means it will only be uploaded to YouTube, but not included in the ACM DL.

Expectations of authors during the conference:

  • Be present for the presentation in both of your sessions (~7 minute pre-recorded talk), followed by live discussion / Q&A with the audience (up to 15 minutes total per paper). While co-authors can be present for the live discussion / Q&A on the Zoom call, we ask that authors decide in advance who answers which types of questions. All questions will be posed to the main presenter, who may defer to a co-author on the call. Sessions will be held via Zoom webinar in dedicated “rooms”. Attendees can ask questions on the room’s Discord channel, which the session chair will relay to the presenters.
  • Note that this is not only a live Q&A, but authors can also pose questions or discussion points to the audience either as part of their pre-recorded talk, in advance on Discord, or during the live discussion. We are expecting that some attendees might already have read the papers in advance since pre-prints will be released already two months prior to the conference.
  • Asynchronous conversation on Discord. Each paper will get a dedicated Discord channel for asynchronous conversations with the audience before and after the presentation.

We are looking forward to a Global UIST 2021!

Amy Pavel, Can Liu, Frederik Brudy (Digital Participation Chairs)
Jeff Nichols (General Chair)