Conferences – Machine Learning (Theory)

7/19/20217/19/2021

ICML 2021 Invited Speakers — ML for Science

By: Stefanie Jegelka and Ameet Talwalkar (ICML21 Communication Chairs)

With ICML 2021 underway, we wanted to briefly highlight the upcoming invited talks. A general theme of the invited talks this year is “machine learning for science.” The Program Chairs (Marina Meila and Tong Zhang) have invited world-renowned scientists from various disciplines to discuss their problems and the corresponding machine learning challenges. By exposing the machine learning community to these fascinating problems, we hope that we can help to further expand the applicability of machine learning to a wide range of scientific domains.

Daphne Koller (Tuesday, July 20th at 8am PDT): Dr. Koller is a pioneer in the field of machine learning, and is currently the Founder and CEO of Insitro, which leverages machine learning for drug discovery. She was the Rajeev Motwani Professor of Computer Science at Stanford University, where she served on the faculty for 18 years. She was the co-founder, co-CEO and President of Coursera, and the Chief Computing Officer of Calico, an Alphabet company in the healthcare space. She received the MacArthur Foundation Fellowship in 2004, was awarded the ACM Prize in Computing in 2008, and was recognized as one of TIME Magazine’s 100 most influential people in 2012.
Xiao Cunde and Dahe Qin (Tuesday, July 20th at 8pm PDT): Dr. Cunde is a glaciologist and Deputy Director of the Institute of the Climate System, Chinese Academy of Meteorological Sciences. He has worked in the fields of polar glaciology and meteorology since 1997. His major research focus has been ice core studies relating to paleo-climate and paleo-environment, and present day cold region meteorological and glaciological processes that impact environmental and climatic changes. Dr. Qin is the Former Director of the China Meteorological Administration. He is a glaciologist and the first Chinese ever to cross the South Pole. He was a member of the 1989 International Cross South Pole Expedition and has published numerous ground-breaking articles, using evidence gathered from his Antarctic expeditions.
Esther Duflo (Wednesday, July 21st at 8am PDT): Dr. Duflo is the Abdul Latif Jameel Professor of Poverty Alleviation and Development Economics in the Department of Economics at MIT and a co-founder and co-director of the Abdul Latif Jameel Poverty Action Lab (J-PAL). In her research, she seeks to understand the economic lives of the poor, with the aim to help design and evaluate social policies. She has worked on health, education, financial inclusion, environment and governance. In 2019, she received a Nobel Prize in Economic Sciences “for their experimental approach to alleviating global poverty”. In particular, she and co-authors have introduced a new approach to obtaining reliable answers about the best ways to fight global poverty.
Edward Chang (Wednesday, July 21st at 8pm PDT): Dr. Chang is a Professor in the Department of Neurological Surgery at the UCSF Weill Institute for Neurosciences. He is a neurosurgeon and uses machine learning to understand brain functions. His research focuses on the brain mechanisms for speech, movement and human emotion. He co-directs the Center for Neural Engineering and Prostheses, a collaborative enterprise of UCSF and UC Berkeley. The center brings together experts in engineering, neurology and neurosurgery to develop state-of-the-art biomedical technology to restore function for patients with neurological disabilities such as paralysis and speech disorders.
Cecilia Clementi (Thursday, July 22nd at 8am PDT): Dr. Clementi is a Professor of Chemistry, and Chemical and Biomolecular Engineering, and Senior Scientist in the Center for Theoretical Biological Physics at Rice University, and an Einstein Fellow at FU Berlin. She researches strategies to study complex biophysical processes on long timescales, and she is an expert in the simulation of biomolecules using large-scale ML. Her group designs multiscale models, adaptive sampling approaches, and data analysis tools, and uses both data-driven methods and theoretical formulations.

To register for the conference and check out these talks, please visit: https://icml.cc/.

12/14/202012/14/2020

What is the Right Response to Employer Misbehavior in Research?

I enjoyed my conversations with Timnit when she was in the MSR-NYC lab, so her situation has been on my mind throughout NeurIPS.

Piecing together what happened second-hand is always tricky, but Jeff Dean’s account and Timnit’s agree on a basic outline. Timnit and others wrote a paper for FAccT which was approved for submission by the normal internal review process, then later unapproved. Timnit threatened to leave unless various details about this unapproval were clarified. Google then declared her resigned.

The definition of resign makes it clear an employee does it, not an employer. Since that apparently never happened, this is a mischaracterized firing. It also seems quite credible that the unapproval process was highly unusual based on various reactions I’ve seen and my personal expectations of what researchers would typically tolerate.

This frankly looks bad to me and quite a number of other people. Aside from the plain facts, this is also consistent with racism and/or sexism given the roles of those involved. Google itself now faces a substantial rebellion amongst employees.

However, I worry about consequences to some of these reactions.

Some people suggest not reviewing papers from Google-based researchers. As a personal decision, this is making a program chair’s difficult job harder. As a communal decision, this would devastate the community since a substantial fraction are employed at Google. These people did not make this decision and many actively support Timnit there (at some risk to their job) so a mass-punishment approach seems deeply counterproductive.
Others have suggested that Google should not be a sponsor at major machine learning conferences. Since all of these are run as nonprofits, the lost grants will either be made up by increasing costs for everyone or reducing grants to students and diversity sponsorship. Reduced grants in particular seem deeply counterproductive.
Some have suggested that all industry research in general is bad. Industrial research varies substantially from place to place, perhaps much more so than in academia. As an example, Microsoft Research has no similar internal review process for publications. Overall, the stereotyping inherent in this view makes me uncomfortable and there are some real advantages to working in industry in terms of ability to concentrate on research or effecting real change.

It’s critical to understand that the strength of the research community is incredibly valuable to the community. It’s not hard to imagine a different arrangement where all industrial research is proprietary, with only a few major companies operating competitive internal research teams. This sort of structure exists in some other fields, often to the detriment of anyone other than a major company. Researchers at those companies can’t as easily switch jobs and researchers outside of those companies may lack the context to even contribute to the state of the art. The field itself progresses slower and in a more secretive way due to lack of sharing. Anticommunal acts based on mass ostracization or abandonment could shift our structure from the current relatively happy equilibrium where people from all over can participate, learn, and contribute towards a much worse situation.

This is not to say that there are no consequences. The substantial natural consequences of a significant moral-impacting event will play out regardless of anything else. The marketplace for top researchers is quite competitive so for many of them uncertainty about the feasibility of publication, the disposition and competence of senior leadership, or constraints on topics tips the balance towards other offers. That may be severe this year, since this all blew up as the recruiting season was launching and I expect it to last over many years unless some significant action is taken. In this sense, I expect all the competitors may be looking forward to recruiting more than they were previously and the cost of not resolving the conflict here in a better way may be much, much higher than just about any other course of action. This is not particularly hypothetical—I saw it play out over the years after the silicon valley lab was cut as the brain drain of other great researchers in competitive areas was severe for several years afterwards.

I don’t think a general answer to the starting question is possible, since it will always depend on circumstances. Even this instance is complex with actions that could cause unintuitive adverse impacts on unanticipated parts of our community or damage the community as a whole. I personally hope that the considerable natural consequences here form a substantial deterrent to misbehavior in the long term. Please think this through when considering your actions here.

Edits: tweaked conclusion wording a bit with advice from reshamas.

12/1/2020

Experiments with the ICML 2020 Peer-Review Process

This post is cross-listed on the CMU ML blog.

The International Conference on Machine Learning (ICML) is a flagship machine learning conference that in 2020 received 4,990 submissions and managed a pool of 3,931 reviewers and area chairs. Given that the stakes in the review process are high — the careers of researchers are often significantly affected by the publications in top venues — we decided to scrutinize several components of the peer-review process in a series of experiments. Specifically, in conjunction with the ICML 2020 conference, we performed three experiments that target: resubmission policies, management of reviewer discussions, and reviewer recruiting. In this post, we summarize the results of these studies.

Resubmission Bias

Motivation. Several leading ML and AI conferences have recently started requiring authors to declare previous submission history of their papers. In part, such measures are taken to reduce the load on reviewers by discouraging resubmissions without substantial changes. However, this requirement poses a risk of bias in reviewers’ evaluations.

Research question. Do reviewers get biased when they know that the paper they are reviewing was previously rejected from a similar venue?

Procedure. We organized an auxiliary conference review process with 134 junior reviewers from 5 top US schools and 19 papers from various areas of ML. We assigned participants 1 paper each and asked them to review the paper as if it was submitted to ICML. Unbeknown to participants, we allocated them to a test or control condition uniformly at random:

Control. Participants review the papers as usual.

Test. Before reading the paper, participants are told that the paper they review is a resubmission.

Hypothesis. We expect that if the bias is present, reviewers in the test condition should be harsher than in the control.

Key findings. Reviewers give almost one point lower score (95% Confidence Interval: [0.24, 1.30]) on a 10-point Likert item for the overall evaluation of a paper when they are told that a paper is a resubmission. In terms of narrower review criteria, reviewers tend to underrate “Paper Quality” the most.

Implications. Conference organizers need to evaluate a trade-off between envisaged benefits such as the hypothetical reduction in the number of submissions and the potential unfairness introduced to the process by the resubmission bias. One option to reduce the bias is to postpone the moment in which the resubmission signal is revealed until after the initial reviews are submitted. This finding must also be accounted for when deciding whether the reviews of rejected papers should be publicly available on systems like openreview.net and others.

Details. http://arxiv.org/abs/2011.14646

Herding Effects in Discussions

Motivation. Past research on human decision making shows that group discussion is susceptible to various biases related to social influence. For instance, it is documented that the decision of a group may be biased towards the opinion of the group member who proposes the solution first. We call this effect herding and note that, in peer review, herding (if present) may result in undesirable artifacts in decisions as different area chairs use different strategies to select the discussion initiator.

Research question. Conditioned on a set of reviewers who actively participate in a discussion of a paper, does the final decision of the paper depend on the order in which reviewers join the discussion?

Procedure. We performed a randomized controlled trial on herding in ICML 2020 discussions that involved about 1,500 papers and 2,000 reviewers. In peer review, the discussion takes place after the reviewers submit their initial reviews, so we know prior opinions of reviewers about the papers. With this information, we split a subset of ICML papers into two groups uniformly at random and applied different discussion-management strategies to them:

Positive Group. First ask the most positive reviewer to start the discussion, then later ask the most negative reviewer to contribute to the discussion.

Negative Group. First ask the most negative reviewer to start the discussion, then later ask the most positive reviewer to contribute to the discussion.

Hypothesis. The only difference between the strategies is the order in which reviewers are supposed to join the discussion. Hence, if the herding is absent, the strategies will not impact submissions from the two groups disproportionately. However, if the herding is present, we expect that the difference in the order will introduce a difference in the acceptance rates across the two groups of papers.

Key findings. The analysis of outcomes of approximately 1,500 papers does not reveal a statistically significant difference in acceptance rates between the two groups of papers. Hence, we find no evidence of herding in the discussion phase of peer review.

Implications. Regarding the concern of herding which is found to occur in other applications involving people, discussion in peer review does not seem to be susceptible to this effect and hence no specific measures to counteract herding in peer-review discussions are needed.

Details. https://arxiv.org/abs/2011.15083

Novice Reviewer Recruiting

Motivation. A surge in the number of submissions received by leading ML and AI conferences has challenged the sustainability of the review process by increasing the burden on the pool of qualified reviewers. Leading conferences have been addressing the issue by relaxing the seniority bar for reviewers and inviting very junior researchers with limited or no publication history, but there is mixed evidence regarding the impact of such interventions on the quality of reviews.

Research question. Can very junior reviewers be recruited and guided such that they enlarge the reviewer pool of leading ML and AI conferences without compromising the quality of the process?

Procedure. We implemented a twofold approach towards managing novice reviewers:

Selection. We evaluated reviews written in the aforementioned auxiliary conference review process involving 134 junior reviewers, and invited 52 of these reviewers who produced the strongest reviews to join the reviewer pool of ICML 2020. Most of these 52 “experimental” reviewers come from the population not considered by the conventional way of reviewer recruiting used in ICML 2020.

Mentoring. In the actual conference, we provided these experimental reviewers with a senior researcher as a point of contact who offered additional mentoring.

Hypothesis. If our approach allows to bring strong reviewers to the pool, we expect experimental reviewers to perform at least as good as reviewers from the main pool on various metrics, including the quality of reviews as rated by area chairs.

Key findings. A combination of the selection and mentoring mechanisms results in reviews of at least comparable and on some metrics even higher-rated quality as compared to the conventional pool of reviews: 30% of reviews written by the experimental reviewers exceeded the expectations of area chairs (compared to only 14% for the main pool).

Implications. The experiment received positive feedback from participants who appreciated the opportunity to become a reviewer in ICML 2020 and from authors of papers used in the auxiliary review process who received a set of useful reviews without submitting to a real conference. Hence, we believe that a promising direction is to replicate the experiment at a larger scale and evaluate the benefits of each component of our approach.

Details. http://arxiv.org/abs/2011.15050

Conclusion

All in all, the experiments we conducted in ICML 2020 reveal some useful and actionable insights about the peer-review process. We hope that some of these ideas will help to design a better peer-review pipeline in future conferences.

We thank ICML area chairs, reviewers, and authors for their tremendous efforts. We would also like to thank the Microsoft Conference Management Toolkit (CMT) team for their continuous support and implementation of features necessary to run these experiments, the authors of papers contributed to the auxiliary review process for their responsiveness, and participants of the resubmission bias experiment for their enthusiasm. Finally, we thank Ed Kennedy and Devendra Chaplot for their help with designing and executing the experiments.

The post is based on the works by Ivan Stelmakh, Nihar B. Shah, Aarti Singh, Hal Daumé III, and Charvi Rastogi.

2/23/2020

Coronavirus and Machine Learning Conferences

I’ve been following the renamed COVID-19 epidemic closely since potential exponentials deserve that kind of attention.

The last few days have convinced me it’s a good idea to start making contingency plans for machine learning conferences like ICML. The plausible options happen to be structurally aligned with calls to enable reduced travel to machine learning conferences, but of course the need is much more immediate.

I’ll discuss relevant observations about COVID-19 and then the impact on machine learning conferences.

COVID-19 observations

COVID-19 is capable of exponentiating with a base estimated at 2.13-3.11 and a doubling time around a week when unchecked.
COVID-19 is far more deadly than the seasonal flu with estimates of a 2-3% fatality rate but also much milder than SARS or MERS. Indeed, part of what makes COVID-19 so significant is the fact that it is mild for many people leading to a lack of diagnosis, more spread, and ultimately more illness and death.
COVID-19 can be controlled at a large scale via draconian travel restrictions. The number of new observed cases per day peaked about 2 weeks after China’s lockdown and has been declining for the last week.
COVID-19 can be controlled at a small scale by careful contact tracing and isolation. There have been hundreds of cases spread across the world over the last month which have not created new uncontrolled outbreaks.
New significant uncontrolled outbreaks in Italy, Iran, and South Korea have been revealed over the last few days. Some details:
1. The 8 COVID-19 deaths in Iran suggests that the few reported cases (as of 2/23) are only the tip of the iceberg.
2. The fact that South Korea and Italy can suddenly discover a large outbreak despite heavy news coverage suggests that it can really happen anywhere.
3. These new outbreaks suggest that in a few days COVID-19 is likely to become a world-problem with a declining China aspect rather than a China-problem with ramifications for the rest of the world.

There remains quite a bit of uncertainty about COVID-19, of course. The plausible bet is that the known control measures remain effective when and where they can be exercised with new ones (like a vaccine) eventually reducing it to a non-problem.

Conferences
The plausible scenario leaves conferences still in a delicate position because they require many things go right to function. We can easily envision 3 quite different futures here consistent with the plausible case.

Good case New COVID-19 outbreaks are systematically controlled via proven measures with the overall number of daily cases declining steadily as they are right now. The impact on conferences is marginal with lingering travel restrictions affecting some (<10%) potential attendees.
Poor case Multiple COVID-19 outbreaks turn into a pandemic (=multi-continent epidemic) in regions unable to effectively exercise either control measure. Outbreaks in other regions occur, but they are effectively controlled. The impact on conferences is significant with many (50%?) avoiding travel due to either restrictions or uncertainty about restrictions.
Bad case The same as (2), except that an outbreak occurs in the area of the conference. This makes the conference nonviable due to travel restrictions alone. It’s notable here that Italy’s new outbreak involves travel lockdowns a few hundred miles/kilometers from Vienna where ICML 2020 is planned.

Even the first outcome could benefit from some planning while gracefully handling the last outcome requires it.

The obvious response to these plausible scenarios is to reduce the dependence of a successful conference on travel. To do this we need to think about what a conference is in terms of the roles that it fulfills. The quick breakdown I see is:

Distilling knowledge. Luckily, our review process is already distributed.
Passing on knowledge.
Meeting people, both old friends and discovering new ones.
Finding a job / employee.

How (and which) of these can be effectively supported remotely?

I’m planning to have discussions over the next few weeks about this to distill out some plans. If you have good ideas, let’s discuss. Unlike most contingency planning, it seems likely that efforts are not wasted no matter what the outcome 🙂

2/26/2019

Code submission should be encouraged but not compulsory

ICML, ICLR, and NeurIPS are all considering or experimenting with code and data submission as a part of the reviewer or publication process with the hypothesis that it aids reproducibility of results. Reproducibility has been a rising concern with discussions in paper, workshop, and invited talk.

The fundamental driver is of course lack of reproducibility. Lack of reproducibility is an inherently serious and valid concern for any kind of publishing process where people rely on prior work to compare with and do new things. Lack of reproducibility (due to random initialization for example) was one of the things leading to a period of unpopularity for neural networks when I was a graduate student. That has proved nonviable (Surprise! Learning circuits is important!), but the reproducibility issue remains. Furthermore, there is always an opportunity and latent suspicion that authors ‘cheat’ in reporting results which could be allayed using a reproducible approach.

With the above said, I think the reproducibility proponents should understand that reproducibility is a value but not an absolute value. As an example here, I believe it’s quite worthwhile for the community to see AlphaGoZero published even if the results are not necessarily easily reproduced. There is real value for the community in showing what is possible irrespective of whether or not another game with same master of Go is possible, and there is real value in having an algorithm like this be public even if the code is not. Treating reproducibility as an absolute value could exclude results like this.

An essential understanding here is that machine learning is (at least) 3 different kinds of research.

Algorithms: The goal is coming up with a better algorithm for solving some category of learning problems. This is the most typical viewpoint at these conferences.
Theory: The goal is generally understanding what is possible or not possible for learning algorithms. Although these papers may have algorithms, they are often not the point and demanding an implementation of them is a waste of time for author, reviewer, and reader.
Applications: The goal is solving some particular task. AlphaGoZero is a reasonable example of this—it was about beating the world champion in Go with algorithmic development in service of that. For this kind of research perfect programmatic reproducibility may be infeasible because the computation is to extreme, the data is proprietary, etc…

Using a one-size-fits-all approach where you demand that every paper “is” a programmatically reproducible implementation is a mistake that would create a division that reduces our community. Keeping this three-fold focus fundamentally enriches the community both literally and ontologically.

Another view here is provided by considering the argument at a wider scope. Would you prefer that health regulations/treatments be based on all scientific studies including those where data is not fully released to the public (i.e almost all of them for privacy reasons)? Or would you prefer that health regulations/treatments be based only on data fully released to the public? Preferring the latter is equivalent to ignoring most scientific studies in making decisions.

The alternative to a compulsory approach is to take an additive view. The additive approach has a good track record amongst reviewing process changes.

When I was a graduate student, papers were not double blind. The community switched to double blind because it adds an opportunity for reviewers to review fairly and it gives authors a chance to have their work reviewed fairly whether they are junior or senior. As a community we also do not restrict posting on arxiv or talks about a paper before publication, because that would subtract from what authors can do. Double blind reviewing could be divisive, but it is not when used in this fashion.
When I was a graduate student, there was also a hard limit on the number of pages in submissions. For theory papers this meant that proofs were not included. We changed the review process to allow (but not require) submission of an appendix which could optionally be used by reviewers. This again adds to the options available to authors/reviewers and is generally viewed as positive by everyone involved.

What can we add to the community in terms reproducibility?

Can reviewers do a better job of reviewing if they have access to the underlying code or data?
Can authors benefit from releasing code?
Can readers of a paper benefit from an accompanying code release?

The answer to each of these question is a clear ‘yes’ if done right.

For reviewers, it’s important to not overburden them. They may lack the computational resources, platform, or personal time to do a full reproduction of results even if that is possible. Hence, we should view code (and data) submission in the same way as an appendix which reviewers may delve into and use if they so desire.

For authors, code release has two benefits—it provides an additional avenue for convincing reviewers who default to skeptical and it makes followup work significantly more likely. My most cited paper was Isomap which did indeed come with a code release. Of course, this is not possible or beneficial for authors in many cases. Maybe it’s a theory paper where the algorithm isn’t the point? Maybe either data or code can’t be fully released since it’s proprietary? There are a variety of reasons. From this viewpoint we see that releasing code should be supported and encouraged but optional.

For readers, having code (and data) available obviously adds to the depth of value that a paper has. Not every reader will take advantage of that but some will and it enormously reduces the barrier to using a paper in many cases.

Let’s assume we do all of these additive and enabling things, which is about where Kamalika and Russ aimed the ICML policy this year.

Is there a need for go further towards compulsory code submission? I don’t yet see evidence that default skeptical reviewers aren’t capable of weighing the value of reproducibility against other values in considering whether a paper should be published.

Should we do less than the additive and enabling things? I don’t see why—the additive approach provides pure improvements to the author/review/publish process. Not everyone is able to take advantage of this, but that seems like a poor reason to restrict others from taking advantage when they can.

One last thing to note is that this year’s code submission process is an experiment. We should all want program chairs to be able to experiment, because that is how improvements happen. We should do our best to work with such experiments, try to make a real assessment of success/failure, and expect adjustments for next year.