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ITC 2020 program is out

June 4, 2020

Guest post by Benny Applebaum

The ITC 2020 program is out, and this newborn looks healthy and strong! The program contains exciting new works in the area of Information-Theoretic Cryptography, confirming the importance of this new venue.

The PC, chaired by Daniel Wichs, also chose an amazing sequence of invited talks by Dachman-Soled, Natarajan, Jafar, Kol, Raz, and Vaikuntanathan, so this can also be a good opportunity to hear about the big recent developments in the area.

The conference will be virtual this year. Participation is free but requires registration. We hope to see many of you there

Theory of Machine Learning summer seminar

June 1, 2020

[Note: While I and many others are fortunate to be able to go on with our work, deadlines, and (as mentioned in this post) seminars, this is not the case for many in the U.S. following yet another demonstration that black lives don’t matter as much as they should in this country. I would like to relay Rediet Abebe’s call to support local organizations. As Rediet says “These problems have been and will be here for a very long time. We’re not solving racism this month.”. –Boaz]

For the last year, I have been co organizing a theory of machine learning seminar at Harvard. Following the format of our prior Harvard/MSR/MIT theory reading group, these have been extended blackboard talks with plenty of audience interaction.

Following COVID-19, the last three talks in the semester (by Moritz Hardt, Zico Kolter, and Anima Anandkumar) were given virtually. Frankly, I was at first unsure whether these seminars can work in the virtual format but was pleasantly surprised. Talks have been very interactive, with plenty of audience participation in the chat channel. In fact, the virtual format has some advantages over physical talks. Sometimes a question will be asked and answered by a co-author over chat, without the speaker needing to interrupt the talk.

Since the seminars were so successful, we decided to continue holding them over the summer. We have an exciting line up of confirmed speakers, and more will come soon. See our webpage for more details, which also contains a google calendar and a mailing list you can sign up for to get the Zoom link.

Confirmed speakers so far include:

More should be confirmed soon – join our mailing list to get updates.

Liberation from grades

May 29, 2020

This semester, like many other universities, Harvard switched to a pass/fail grade model. (In typical Harvard style, we give them different names – “Emergency Satisfactory” and “Emergency Unsatisfactory” – but that doesn’t matter much).

One unexpected but happy consequence of this policy is that even though I already submitted the grades for my crypto course, I can now take the time and send students detailed feedback on their final projects. Typically, both students and faculty tend to be focused on the “bottom line” of exams or papers – what is the final grade. The comments are viewed as of marginal importance and only serve to justify why points have been deducted.

Now that there is no grade, I am actually giving many more comments on the write ups, trying to focus on giving students feedback on writing and presentation that will be useful for them later on. I benefited immensely from the extensive comments on my writing that I received from my advisor Oded Goldreich. While I will never match Oded’s thoroughness and dedication, I try to at least provide some of this to my students (though unlike Oded, I use blue and not red ink, and also do not intersperse the comments with Hebrew curses for emphasis 🙂 )

Foundations of responsible computing

May 17, 2020

[Hat tip: Aaron Roth]

The inaugural conference on the foundations of responsible computing will take place in less than two weeks (June 1-2). Registration is FREE but you need to register by May 28.

The program looks fantastic, and includes keynotes by Adrian Weller, Rakesh Vohra, Patricia Williams, and Jon Kleinberg, as well as a set of (very interesting, judging by the titles) contributed talks.

Resources for the upcoming job market crunch

May 13, 2020

Aside from its devastating death toll, the COVID-19 pandemic has had severe economic implications. The impact on universities is particularly substantial, including disruptions to our physical campuses and student residences, as well as to the sources of income for private and public universities such as endowments and state budgets.

All this means that the academic job market is likely going to be tough in the near future, and computer science will not be immune. During the last recession, the CCC started a computing innovation fellows program which was very successful, and I hope that something similar will occur this time as well. But it won’t be enough.

If you are aware of any postdoc positions (or better yet, can create one) please do make sure to post it on the CS theory job board. If you know of any teaching position that could potentially be applicable for theorists, please post it there too. This crisis can also be an opportunity to get fantastic people for such positions. If you have any ideas on how we as the theoretical CS community can support graduating students and postdocs, please do share these in the comments or on Twitter.

If anything, this crisis has taught us that the world needs more science, not less. Moreover, computer science has been and will continue to be a crucial component in fighting this epidemic, including not just modeling but also tracing applications using crypto, load balancing that ensures the Internet doesn’t crush, and more. I am thus hopeful that within a couple of years, the academic job market for theoretical computer scientists will recover. However we should try to do all we can to help our junior colleagues get through this period.

Lessons from COVID-19: What works online and what doesn’t

April 27, 2020

(I am now on Twitter , so you can follow this blog there too if you prefer it. –Boaz)

Between Zoom meetings and deadlines, I thought I’d jot down a few of my impressions so far on what lessons we can draw from this period on how well research and education can work online. I’ve had a few surprises in both directions – things that worked better than I would have expected, and aspects that were more problematic than I realized. These are personal impressions – please do comment on your own experiences.

As a rule of thumb, the interactions that most successfully replicate online are those that are relatively short and focused (an hour or so – e.g., a focused research meeting, seminar talk, or a lecture in a course). Other interactions (e.g., faculty meetings) are also fairly easily to port online, perhaps because the original wasn’t that great to begin with.

The things that are harder to replicate are sustained interactions over longer periods. These include more extended and less directed research collaborations, informal workshops, as well as support for students outside lectures in education.

Works well: Research seminars

I’ve been pleasantly surprised by how effective research seminars such as our machine learning theory seminar are over Zoom. In particular these were no less interactive than physical seminars – in fact people are offten more comfortable asking questions on chat than they would during in-person seminars. I hope such seminars become common practice even after this period ends- flying a speaker across the country or the world to give an hour talk doesn’t makes much sense given that there is a perfectly satisfactory alternative.

Works well: Lectures

This term I am teaching cryptography, and online lectures on Zoom have gone surprisingly well (after working out some technical issues). Students participate on chat and ask questions, and seem to be following the lecture quite well. The important caveat is that lectures only work well for the students that attend and can follow them. For students who need extra support, it’s become much harder to access it. It’s also much easier for students to (literally) “fall off the screen” and fall behind in a course, which brings me to the next point.

Works less well: Support outside lectures

Lectures are just one component of a course. Most of students’ learning occurs outside the classroom, where students meet together and work on problem sets, or discuss course material. These interactions between students (both related and unrelated to course) are where much of their intellectual growth happens.

All these interactions are greatly diminished online, and I did not yet see a good alternative. I’ve seen reduced attendance in office hours and sections, and reports are that students find it much harder to have the sort of chance discussions and opportunities to find study partners that they value so much. If anything, this experience had made me less positive about the possibility of online education replacing physical colleges (though there are interesting hybrid models, where the students are co-located but lecturers are online).

Works less well: unstructured research collaborations

A focused meeting reporting on results or deciding on work allocation works pretty well over Zoom. So far it seems that extended brainstorming meetings, such as talking to someone over several hours in a coffeeshop, are much harder to replicate. In particular, a good part of such meetings is often spent with people staring in silence into their notebooks. As I wrote, mutual silence seems to be very hard to do over Zoom.

Generally, informal week-long workshops, where much time is devoted to unstructured discussions, are ones that are most important to hold in person, and are hard (or maybe impossible) to replicate online. I have still not attended an online conference, but I suspect that these aspects of the conference would also be the ones hardest to replicate.

Works well: faculty meetings

I’ve always found it hard to bring a laptop to a faculty meeting and get work done, while listening with one ear to what’s going on. This is so much easier over Zoom 🙂

Experts shmexperts

April 9, 2020

(If you’re not already following him, I highly recommend reading Luca Trevisan’s dispatches from Milan, much more interesting than what I write below.)

On the topic of my last post, Ross Douthat writes in the New York Times that “In the fog of coronavirus, there are no experts”, even citing Scott Aaronson’s post. Both Aaronson and Douthat make the point that the COVID-19 crisis is so surprising and unprecedented, and experts were so much in the dark, that there is no reason to trust them over non expert “common sense” or “armchair epidemiologists”.

It’s true that the “expert models” have significant uncertainty, hardwired constants, noisy data, and dubious assumptions. It is also true that many countries (especially those that didn’t learn from the 2003 SARS epidemic) bungled their initial response. But do we really need to challenge the notion of expertise itself? To what extent was this pandemic not predicted by experts or progressed in ways defying their expectations?

Here is what some of these experts and institutions were saying in the recent past:

“The thing I’m most concerned about … is the emergence of a new virus that the body doesn’t have any background experience with, that is very transmissible, highly transmissible from person to person, and has a high degree of morbidity and mortality … a respiratory illness that can spread even before someone is so sick that you want to keep them in bed.” Dr. Anthoni Fauci, 2019.

“High-impact respiratory pathogens … pose particular global risks … [they] are spread via respiratory droplets; they can infect a large number of people very quickly and with today’s transportation infrastructure, move rapidly across multiple geographies. … There is insufficient R&D investment and planning for innovative vaccine development and manufacture, broad-spectrum antivirals, … In addition, such a pandemic requires advance planning across multiple sectors … Epidemic control costs would completely overwhelm the current financing arrangements for emergency response.” WHO world at risk report, 2019.

“respiratory transmission …. is the transmission route posing the greatest pandemic risk … [since it] can occur with coughing or simply breathing (in aerosol transmission), making containment much more challenging. … If a pathogen is capable of causing asymptomatic or mildly symptomatic infections that either do not or only minimally interrupt activities of daily living, many individuals may be exposed. Viruses that cause the common cold, including coronaviruses, have this attribute.” JHU report, 2019.

As an experiment, I also tried to compare the response of experts and “contrarians” in real time as the novel coronavirus was discovered, trying to see if it’s really the case that, as Douthat says, “up until mid-March you were better off trusting the alarmists of anonymous Twitter than the official pronouncements from the custodians of public health”. I chose both experts and contrarians that are active on Twitter. I was initially planning to look at several people but due to laziness am just taking Imperial college’s J-IDEA institute for the expert, and Robin Hanson for the contrarian. I also looked at Douthat’s twitter feed, to see if he followed his own advice. Initially I thought I would go all the way to March but have no time so just looked at the period from January 1 till February 14th. I leave any conclusions to the reader.

January 1-19:

(Context: novel coronavirus confirmed in Wuhan, initially unclear if there is human to human transmission – this was confirmed by China on January 20 though suspected before.)

Here is one of several tweets by Imperial from this period:

I didn’t see any tweets from Hanson or Douthat on this topic.

January 20-31:

(Context: first confirmed cases in several countries, including the US, WHO declares emergency in Jan 30, US restricts travel from China on Jan 31. By then there are about 10K confirmed cases and 213 deaths worldwide.)

On January 25th Imperial college estimated the novel coronavirus “R0” parameter as 2.6:

Hanson tweeted approvingly about China’s response and that this situation might help the “more authoritarian” U.S. presidential candidate:

Still no tweet from Douthat on this topic though he did say in January 29th that compared to issues in the past the U.S.’s problems in the 2020’s are “problem of decadence” rather than any crisis like the late 1970’s:

February 1-14:

(Context: Diamond princess cruise ship quaranteed, disease gets COVID-19 official name, first death in Europe)

Imperial continues to tweet extensively, including the following early estimates of the case fatality rates:

Robin Hanson correctly realizes this is going to spread wide:

Hanson tweets quite a lot about this, including potential social implications. Up to February 13th there is nothing too “contrarian” at this point, but also no information that could not be gotten from the experts:

In February 14 Hansons makes a very contrarian position when he proposes “controlled infection” as a solution:

To the anticipated “you first” objection he responds “I proposed compensating volunteers via cash or medical priority for associates, & I’d seriously consider such offers.”. He doesn’t mention that he is much less strapped for cash than some of the would be “volunteers”.

Still no tweet from Douthat about COVID-19 though he does write that we live in an “age of decadence”:

In defense of expertise

April 4, 2020

Scott Aaronson blogged in defense of “armchair epidemiology”. Scott makes several points I agree with, but he also advocates that rather than discounting ideas from “contrarians” who have no special expertise in the matter, each one of us should evaluate the input of such people on its merits.

I disagree. I can judge on their merits the validity of a proposed P vs NP proof or a quantum algorithm for SAT, but I have seen time and again smart and educated non-experts misjudge such proposals. As much as I’d like to think otherwise, I would probably be fooled just as easily by a well-presented proposal in area X that “brushes under the rug” subtleties that experts in X would immediately notice.

This is not to say that non experts should stay completely out of the matter. Just like scientific journalists such as Erica Klarreich and Kevin Hartnett of quanta can do a great job of explaining computer science topics to lay audience, so can other well-read people serve as “signal boosters” and highlight works of experts in epidemiology. Journalist Helen Branswell of stat news has been following the novel coronavirus since January 4th.

The difference is that these journalists don’t pretend to see what the experts are missing but rather to highlight and simplify the works that experts are already doing. This is unlike “contrarians” such as Robin Hanson that do their own analysis on a spreadsheet and come up with a “home brewed” policy proposal such as deliberate infection or variolation (with “hero hotels” in which people go to be deliberately infected). I am not saying that such proposals are necessarily wrong, but I am saying that I (or anyone else without the experience in this field) am not qualified to judge them. Even if they did “make sense” to me (they don’t) I would not feel any more confident in judging them than I would in reviewing a paper in astronomy. There is a reason why Wikipedia has a “no original research” policy.

Moreover, the attitude of dismissing expertise can be dangerous, whether it comes in the form of “teach the debate” in the context of evolution, or “ClimateGate” in the context of climate change. Unlike the narrative of few brave “dissenters” or “contrarians”, in the case of COVID-19, experts as well as the world health organization have been literally sounding the alarm (see also timeline, as well as this NPR story on the US response). Yes, some institutions, and especially the U.S., failed in several aspects (most importantly in the early production of testing). But one of the most troubling aspects is the constant sense of “daylight” and distrust between the current U.S. administration and its own medical experts. Moreover, the opinions of people such as law professor Richard Epstein are listened to even when they are far out of their depth. It is one thing to entertain the opinion of non-expert contrarians when we have all the time in the world to debate, discuss and debunk. It’s quite another to do so in the context of a fast-moving health emergency. COVID-19 is an emergency that has medical, social, economical, and technological aspects, but it would best be addressed if each person contributes according to their skill set and collaborates with people of complementary backgrounds.

Technology for theory: COVID-19 edition

March 26, 2020

The new coronavirus upended much of society, including our little corner of it. I believe at this point almost all theorists are teaching and doing research at home, and I thought it would be good to share some of the tools we use for doing so. Below I will describe my setup, but I hope other people share theirs too.

Teaching and virtual whiteboards

I am teaching using Zoom and using an iPad pro with a pencil to simulate a whiteboard. I use a laptop to connect to Zoom and for the camera, laptop, and chat window, and then join the iPad.There are several ways to connect an iPad to a Zoom session:

  1. Join the session from the iPad separately using the iPad Zoom app. (To do so you might need to logout of your other account.)
  2. Within the Zoom program on your computer you can choose “share screen” and then one of the option is to join an iPad connected to the same wireless network as the laptop/desktop and use “screen mirroring” on the iPad. (You can find the screen mirroring option on the iPad by swiping from the top right corner in a diagonal motion.)
  3. Another variant of this is to use a third party app such as Reflector 3. Reflector 3 sets up an airplay server on your PC so you can mirror the iPad screen to it. You can then share the Reflector 3 window from Zoom (see screen shorts below). If you do use Reflector 3, you can remove its annoying iPad like frame.
  4. You can use a wired connection, which is either by just connecting through USB (in a Mac) or a complex combination of combining an adapter to take an HDMI signal out of an iPad with an HDMI capture card to stream this signal to the computer.

I use either option 2 or 3. (Might have used 4 if I had a Mac.) The main reason I prefer these to option 1 is because the application I use for a whiteboard – GoodNotes – has a presentation mode that behaves differently when you are connected to an external display or use AirPlay (which is what options 2 and 3 do). In this presentation mode the students don’t see your interface, and so you can Zoom, go to the page selector and more without it disturbing what they see. GoodNotes also has a great “laser pointer”. I set the pages at a landscape orientation, and pre-write a good chunk of what I plan to present before the lecture. I also use the ability to “duplicate pages” to achieve the PowerPoint like effect of gradual reveal.

It is not perfect – I’ve discovered that the screen share sometimes stops refreshing and I need to leave GoodNotes and return to it for it to go back (this seems to works better in Reflector 3 so far for me).

Monitoring the chat window and raised hands in Zoom is non-trivial. It helps a lot that I have a teaching assistant that participates in lecture and notices if I missed something.

Some people say that a “matte screen protector” such as PaperLike makes the iPad more comfortable to write on – haven’t yet tried it. (Update 4/1/2020: I now tried PaperLike and can vouch for it – it greatly improves my handwriting! shipping from the UK did take some time though.)

I have a good Webcam (Logitech Brio) but at the moment I’m not using it since it seems too taxing on my laptop and so I went back to the native webcam. I have a very nice wireless headset/mic combo (Jabra Evolve 75) that I am constantly using and have been very happy with. I particularly like the feature of being able to unmute and mute yourself by raising and lowering the mike.

Using Screen share from Zoom to either share an iPad or the Reflector 3 window
Choose which source to mirror the screen to on your iPad screen
You can reach the screen mirroring options by swiping from the top right corner of the iPad.


For research Slack continues to extremely useful. For working jointly on a paper Overleaf is of course great, but for maintaining a shared document it sometimes useful to use simpler platform that are not full fledged LaTeX. Some options include:

Google JamBoard is an interactive whiteboard, also with an iPad app. I haven’t tried it yet but it seems promising.

Keeping children busy

For many people I imagine childcare is one of the most challenging aspects. At the moment at least the Cambridge Public Schools are not keeping my kids too busy. While probably most of their time is spent in non educational pursuits, we try to also encourage (i.e., bribe/extort/threaten/beg) them to do some learning. If your kids are interested in math, I highly recommend the courses offered by the Art of Problem Solving (they also have a theory connection: one of their books was co-authored by theorist Ravi Boppana). For younger kids you can also try their Beast Academy.

The AOPS program is not free but over the years my kids (especially my 13 year old daughter Alma) have also spent a lot of time on the free and amazing Khan Academy. In fact, last year she was inspired enough by Khan’s JavaScript course to write the following poem which (for obvious reasons) moved me very much:

Tending / Alma Barak

My mind is a desert
of boredom
of blankness
of leaning-back-in-your-chairness
and of simply-staring-at-the-ceilingness
I kick at a crumpled
deserted baby-blonde post-it
with my spotted socked feet
waiting for Aba to come.

We dive when he comes
into the seas of Khan
free-styling our way
into the lakes of Java
we pass codes we already
while loops
for loops
reminding me of what I’d learned

We frog-kick to an
lagoon of code I don’t know
sometimes I get swept away by currents
of confusion
but my aba, my dad
grabs my hand
and shows me the way through
teaching me
tending to me
washing away the sands of boredom with the sea of Khan.

New CS theory talk aggragator

March 25, 2020

Shcachar Lovett has put together a new website aggregating information about virtual talks in CS theory:

 It has a Google calendar that people can add to their own, and a form to submit a new talk that automatically gets added to the Google calendar. 

This can be a fantastic resource these days that almost no one can travel – please publicize this and also submit to it talks that you are organizing.