I recently attended the 27th International Joint Conference on Artificial Intelligence (IJCAI) in Stockholm, Sweden. Unlike what I did for UAI 2017 and ICRA 2018, I won’t be able to write daily blog posts about the conference. In part, this is because I got struck by some weird flu-like and fever symptoms on my flight to Sweden, which sapped my energy. I thought I was clever when my original plan was to rig my sleep schedule so that I’d skip sleep during my last night in the United States, and then get a full 8-hours’ worth of sleep on the flight to Stockholm, upon which I’d arrive at 7:00am (in Stockholm time) feeling refreshed. Unfortunately, my lack of sleep probably exacerbated the unexpected illness, so that plan went out of whack.

On a more positive note, here were some of the highlights of IJCAI. I’ll split this into three main sections, followed by some concluding comments and the photos I took.

Keynote Talks (a.k.a., “Invited Talks”):

  • I enjoyed Yann LeCun’s keynote on Deep Learning. Because it’s Yann LeCun and Deep Learning.
  • Jean-François Bonnefon’s gave a thought-providing talk about The Moral Machine Experiment. Think of what happens with a self-driving car. Suppose it’s in a situation when people are blocking the car’s way, but it’s going too fast to stop. Either it continues going forward (and kills the people in front of it) or it swerves and hits a nearby wall (and kills the passengers). What characteristics of the passengers or pedestrians would cause us to favor which of the two groups to kill?
  • There was also a great talk about “Markets Without Money” by Nicole Immorlica of Microsoft Research. It was a high-level talk discussing some of the theoretical work tying together economics and computer science, about some of the markets we’re engaged in, but which aren’t money-centric. I was reminded of many related books that I’ve been reading about platforms.
  • On the last day there were four invited talks: Andrew Barto for a career achievement award (postponed one year as he was supposed to give it last year), Jitendra Malik for this year’s career achievement award, Milind Tambe for the John McCarthy award, and Stefano Ermon for the IJCAI Computers and Thought award. I enjoyed all the talks.

Workshops, Tutorials, Various Sessions, and Other Stuff:

  • IJCAI had several parallel workshops and tutorials on the first three days, which were co-located with ICML and other AI conferences. I only attended the last day since I had to recover from my illness, and on that day, I attended tutorials about AI and the Law and Predicting Human Decision-Making. They were interesting, though I admit that it was hard to focus after two or three hours. The one on human decision-making, as I predicted, brought up Daniel Kahneman’s 2011 magnus opus Thinking, Fast and Slow, one of my favorite books of all time.
  • There was a crowd-captivating robotics performance during the opening remarks before Yann LeCun’s keynote; a mini-robot and a human actor moved alongside while performing a slow dance-like motion. See my photos — it was entertaining! I’m not sure how the robot was able to conduct such dexterous movements.
  • On the penultimate day, there were back-to-back sessions about AI in Europe. The first featured a lively panel of seven Europeans who opinionated about Europe’s strengths and weaknesses in AI, and what it can do in the future. Several common themes stood out: the need to prevent “brain drain” to the United States and the need for more investment in AI. Notably, the panel’s only mention of Donald Trump was when Max Tegmark (himself one of Europe’s “brain drains!”) criticized America’s leadership and called for Europe to resist Trump when needed. The second session was about Europe’s current AI strategy and consisted of four consecutive talks. They were a bit dry and the speakers spoke with a flat tone while reading directly from text on the slides, so I left early to attend the student reception.
  • Unique to IJCAI, it hosts a “Sister Track for Best Papers.” Authors of papers that won some kind of award in other AI conferences are invited to speak about their work in IJCAI. This is actually why I was there, due to my UAI paper, so I’m grateful that IJCAI includes such sessions.
  • IJCAI also has early career talks. For these, pre-tenure faculty come and give 25-minute talks on their research. This was the most common session I attended (not including keynotes), because faculty tend to be better at giving presentations than graduate students, who make up the bulk of the speakers in most sessions.

Our Social Events:

  • A visit to Skansen, a large open museum, where we could see what a Swedish village might have looked like many years ago. It is a pleasantly surprising mix of a zoo, a hodgepodge of old architecture, and employees acting as ancient Swedish citizens. The Skansen event was joint with ICML and the other co-located conferences, so I saw several Berkeley people (ICML is more popular among us). The food was mediocre, but this was countered by an insane amount of Champagne. Sadly, I was still recovering from my illness and couldn’t drink any.
  • A reception at City Hall, which is most famous for hosting the annual Nobel Prize ceremony. The city of Stockholm actually paid for us, so it wasn’t included as part of any IJCAI registration fees. (They must really want AI researchers to like Sweden!) The bad news? There were over 2000 IJCAI registrants, but City Hall has a strict capacity of 1200, so the only people who could get in were those that skipped the last session of talks that day. I felt this was unfair to those speakers, and I hope if similar scenarios happen in future iterations, IJCAI can hold a lottery and offer a second banquet for those who don’t get in the first one.
  • A conference banquet, held at the Vasa Museum near Skansen. I was excited about attending, but alas, it was closed to students. This was unclear from the conference website and program, and judging from what others said on the Whova app for the conference, I wasn’t the only one confused. That this was not open to students caused one of the faculty attending to boycott the dinner, according to his comments on Whova.
  • To make up for that (I suppose?), there was a student reception the next day, open to students only (obviously). As usual, the wine and beer was great, though the food itself — served cocktail-style — was short of what would qualify as a full dinner. There was a minor steak dish, along with some green soup for vegetarians, but I don’t think the vegetarians were pleased with the options available.
  • A closing reception, at the very end of the conference. It was in the conference venue and offered the usual wine, beer, non-alcoholic drinks, and some small food dishes. There wasn’t much variety in the food offering.

Since I blogged about ICRA 2018 at length, I suppose it’s inevitable to make a (necessarily incomplete) comparison among the two.

In terms of food, ICRA completely outclasses IJCAI. ICRA included lunch (whereas IJCAI didn’t) and the ICRA evening receptions all had far richer food offerings than IJCAI’s. The coffee breaks for ICRA also had better food and drink, including free lattes (ah, the memories…). It looks like the higher registration fees we pay for ICRA are reflected in the proportionately better food and drink quality. The exception may be the alcoholic beverages; the offerings from ICRA and IJCAI seemed to be comparable, though I’ll add that I still haven’t developed the ability to tell great wine from really, really great wine.

ICRA also has a better schedule in that poster sessions were clearly labeled in the schedule, whereas IJCAI’s weren’t explicitly scheduled, meaning that it was technically “all day”. Finally, I think the venue for ICRA — the Brisbane Convention & Exhibition Centre — is better designed than Stockholmsmässan, and furthermore, there’s more interesting stuff within walking distance to Brisbane’s convention. (To mitigate this, IJCAI wisely offered a public transportation card for all attendees.)

That’s not to say ICRA was superior in every metric — far from it! The main advantage of IJCAI is probably that we get to see more of the city itself, as I mention in the social events above.

Here are the photos I took while I was at IJCAI, which I’ve hosted in my Flickr account. (For future conferences I will probably host pictures on Flickr, since I’ve used up a dangerously high amount of my memory allocation for hosting on GitHub.) There are about 150 of them in the album, and I hope you enjoy them.

May 2020 update. The photos were originally private. I have changed the permission settings.