Thursday, August 18, 2022

Conference Modality

We have had an almost normal summer conference season, for some sense of normal. At one of those conferences I participated in an hybrid conversation about whether the conference should be in-person, virtual or hybrid the following year. Here are some general thoughts.


The traditional conference format. People travel from near and far to a hotel, conference center or campus location. Talks given in large rooms, often in parallel. A reception, some social activities, participants gathering in small groups to go out for meals. 

Positives: In-person maximizes interaction between participants. Being physically away from your home means you can focus your time on the conference and your fellow participants. This was more true before the mobile devices/laptops/internet days, but still most participants will spend more time on-site than on-line.

Negatives: Expensive--with registration, hotel and air fare, even a domestic participant could have to pay $2000 or up, higher for those traveling internationally. Visas can be hard to get. Some still feel unsafe in large groups. People often leave early, pity the last speakers. And don't forget the carbon footprint. 

As countries declare war on other countries or states deny certain rights, there is a push against meetings in certain places. Note the disclaimer for next year's FCRC. You might upset some people if you have conferences at these locations (and others if you don't).


Virtual conferences would never in the past have been taken seriously but Covid forced our hands. 

Talks are streamed or pre-recorded. Some interaction with chats in talks, zoom get togethers or though a systems like virtual chair. Even if we had a perfect "metaverse" experience where we could get together as though we were in person, not being there in person means we wouldn't make it a priority.

The big advantages are costs are low, it's easy to attend talks, and no danger of spreading disease. Still a virtual conference can feel too much like just a collection of streamed and recorded talks.


So let's make the conference hybrid and have the best of both worlds. Alas, it doesn't work out that way. It's nearly impossible to have good interaction between in-person and virtual participants--basically you have to run two separate meetings. Do you allow virtual talks or require an author to show up in person. 

How do you set prices? Lower prices for virtual increases assess but decreases in-person attendance. Participants (or their advisors) might opt to save expenses and attend virtually instead of in-person, reducing the networking opportunities for everyone. 

Most conferences tend to take the hybrid route to avoid the complaints if one went fully in-person or virtual, but hybrid just pretty much guarantees a mediocre experience for all.


My suggestion is some years run the conference virtually and others in hybrid. We already have too many conferences, a byproduct of our field using conferences as the primary publication venue. I suggest following conferences like the International Congress of Mathematicians or the Game Theory World Congress, held every four years. If the main conference of a field is held every four years, researchers, particularly senior researchers, make a bigger effort to be there. You can have the virtual meetings the other years so researchers, particularly students, can continue to present their work.

No easy solutions and CS conferences have not worked well for years. Maybe the struggle to define future conferences will allow us to focus more on the connecting researchers than just "journals that meet in a hotel".


  1. A couple of years of remote experience shows that being constantly remote doesn't cut it. It works well for research meetings and at the level of individual talks (though the physical strain and difficulty of concentration in staring at one's personal screen is noticeably greater than in watching a remote talk at a relaxed distance on a large screen where this can become a shared experience). For more extended situations like conferences and workshops, it is a different matter.

    My remote experience for the first time for STOC 2020 was a novelty and I was incentivized to push through and attend a lot. (Remote attendees really did ask lots of good questions in the chat.) Every remote conference since then has been a struggle - time shifts, the physical/mental strain, and the lack of personal connection with most attendees having their cameras off have all made remote attendance an unpleasant experience; I find I only can tolerate a handful of talks per conference.

    This summer it was a joy to be able to attend a couple of in-person conferences and workshops for the first time since January 2020. Technically, they were hybrid events with some talks given remotely by speakers who could not or did not want to travel, but the overwhelming majority of attendees were in person.

    The conference was STOC TheoryFest, with over 400 on-site registrants, which was wonderfully organized by Stefano Leonardi and the TheoryFest committee. It was technically hybrid and some talks were given remotely by authors who could not make it or did not wish to travel. I learned a lot from talking with people in the halls/garden and from talks that I attended that I had no idea would be so interesting. Of course there was the pleasure of meeting old friends for the first time in a long while but, even beyond that, the energy of everything was palpable. In contrast to your claim, I think that "worked well" certainly applied to STOC TheoryFest this year.

    I also participated in two week-long focused workshops:
    - I could attend one in person by combining the travel costs with travel to STOC. Almost all attendees were also in person and it again was a very energizing event where I learned a lot, though there wasn't the aspect of the serendipity of chancing on some cool nugget.
    - I could only attend the other in hybrid fashion, as was the case for about 1/2 to 2/3 of the attendees. I was lucky that the time zone shift was only one hour (which meant being ready to concentrate at 8:00 am) and I only missed two or three talks by not keeping good track of the schedule. It was good, and I still learned a lot but the lack of the side conversations made me feel somewhat disconnected. I got the sense that the small size of the in-person contingent and the fact that so many talks were given remotely cut the effectiveness for those in the room also.

    [This comment is getting long so I'll put my takeaways separately...]

  2. We do need to move away from the extreme mode of constant travel to the multitude of conferences and workshops that we had before the pandemic, due to a variety of costs, but we need to find a way to maintain the energy and serendipitous mixing of ideas that comes from in-person meetings. The question is how we split that up.

    There isn't really a sharp divide between "in-person" and "hybrid" - it just a matter of degree.

    What we mean by an in-person conference should be hybrid in the same sense as STOC was this year - primarily in person but with some remote participation. (Prior to the pandemic, the biggest obstacle to this was technological but thankfully that obstacle is gone.)

    The real question for a conference that is much more hybrid than that (let's say half the speakers are in person and half remote) is how to plan the infrastructure for the size of the in-person component. We don't really have a model and conferences don't have a history for how to plan. Once in-person attendance is too low, it doesn't make sense any more.

    I suspect that less prestigious conferences that don't have a focused specialty will find that they have to become permanently remote to survive and that is probably a good thing. (The focus is on the publication rather than the meeting anyway.)

    The above corresponds to a split in behavior by conference rather than by year within each conference as Lance has suggested.

    Probably the biggest challenge to conference attendance has been the proliferation of excellent workshop venues and specialized workshops. We have Simons, BIRS, DIMACS, Oberwolfach, Dagstuhl, Bertinoro and all of the many workshops at these venues. How well can they work if they aren't primarily in person?

  3. I no longer think in-person conferences are appropriate. I come from a different field where journal publication is the norm, and I strongly agree that having conferences simply as a way of getting prestige (which is the primary purpose of c.s. conferences, whether you will admit it or not!) is just wrong. It's a waste of time and resources (including carbon), and it's unfair to those who may have personal constraints that limit their travel. While I come from a different field, I do have enough work related to comp sci that I have a couple results in good comp sci conferences and I have reviewed for them several times. However, I am strongly re-thinking this. I do not think I will submit to them in future, and I am contemplating refusing to review for conferences on moral grounds.

    1. `whihc is the primary purpose of c.s. conference whether you amid it or not'- Uh, this is a non-controversial point that everyone knows is true and nobody would even think to deny. Whether its a good idea is another matter.

      Actually I AGREE with you that the entire system is expensive and non-productive.I would like to see us do what Math and others do- have regional conferences of low-prestige.