Posted by Shan Carter, Software Engineer and Chris Olah, Research Scientist, Google Brain Team
Science isn't just about discovering new results. It’s also about human understanding. Scientists need to develop notations, analogies, visualizations, and explanations of ideas. This human dimension of science isn't a minor side project. It's deeply tied to the heart of science.
That’s why, in collaboration with OpenAI, DeepMind, YC Research, and others, we’re excited to announce the launch of Distill, a new open science journal and ecosystem supporting human understanding of machine learning. Distill is an independent organization, dedicated to fostering a new segment of the research community.
Modern web technology gives us powerful new tools for expressing this human dimension of science. We can create interactive diagrams and user interfaces the enable intuitive exploration of research ideas. Over the last few years we've seen manyincredibledemonstrationsofthiskindofwork.
Unfortunately, while there are a plethora of conferences and journals in machine learning, there aren’t any research venues that are dedicated to publishing this kind of work. This is partly an issue of focus, and partly because traditional publication venues can't, by virtue of their medium, support interactive visualizations. Without a venue to publish in, many significant contributions don’t count as “real academic contributions” and their authors can’t access the academic support structure.
That’s why Distill aims to build an ecosystem to support this kind of work, starting with three pieces: a research journal, prizes recognizing outstanding work, and tools to facilitate the creation of interactive articles.
Led by a diverse steering committee of leaders from the machine learning and user interface communities, we are very excited to see where Distill will go. To learn more about Distill, see the overview page or read the latest articles.
At Google, we care about giving users the best possible online experience, both through our own services and products and by contributing new tools and industry standards for use by the online community. That’s why we’re excited to announce Guetzli, a new open source algorithm that creates high quality JPEG images with file sizes 35% smaller than currently available methods, enabling webmasters to create webpages that can load faster and use even less data.
Guetzli [guɛtsli] — cookie in Swiss German — is a JPEG encoder for digital images and web graphics that can enable faster online experiences by producing smaller JPEG files while still maintaining compatibility with existing browsers, image processing applications and the JPEG standard. From the practical viewpoint this is very similar to our Zopfli algorithm, which produces smaller PNG and gzip files without needing to introduce a new format, and different than the techniques used in RNN-based image compression, RAISR, and WebP, which all need client and ecosystem changes for compression gains at internet scale.
The visual quality of JPEG images is directly correlated to its multi-stage compression process: color space transform, discrete cosine transform, and quantization. Guetzli specifically targets the quantization stage in which the more visual quality loss is introduced, the smaller the resulting file. Guetzli strikes a balance between minimal loss and file size by employing a search algorithm that tries to overcome the difference between the psychovisual modeling of JPEG's format, and Guetzli’s psychovisual model, which approximates color perception and visual masking in a more thorough and detailed way than what is achievable by simpler color transforms and the discrete cosine transform. However, while Guetzli creates smaller image file sizes, the tradeoff is that these search algorithms take significantly longer to create compressed images than currently available methods.
Figure 1. 16x16 pixel synthetic example of a phone line hanging against a blue sky — traditionally a case where JPEG compression algorithms suffer from artifacts. Uncompressed original is on the left. Guetzli (on the right) shows less ringing artefacts than libjpeg (middle) and has a smaller file size.
And while Guetzli produces smaller image file sizes without sacrificing quality, we additionally found that in experiments where compressed image file sizes are kept constant that human raters consistently preferred the images Guetzli produced over libjpeg images, even when the libjpeg files were the same size or even slightly larger. We think this makes the slower compression a worthy tradeoff.
Figure 2. 20x24 pixel zoomed areas from a picture of a cat’s eye. Uncompressed original on the left. Guetzli (on the right) shows less ringing artefacts than libjpeg (middle) without requiring a larger file size.
It is our hope that webmasters and graphic designers will find Guetzli useful and apply it to their photographic content, making users’ experience smoother on image-heavy websites in addition to reducing load times and bandwidth costs for mobile users. Last, we hope that the new explicitly psychovisual approach in Guetzli will inspire further image and video compression research.
Posted by Jeff Dean, Google Senior Fellow and Leslie Phillips, Google Brain Residency Program Manager
“Beyond being incredibly instructive, the Google Brain Residency program has been a truly affirming experience. Working alongside people who truly love what they do--and are eager to help you develop your own passion--has vastly increased my confidence in my interests, my ability to explore them, and my plans for the near future.” -Akosua Busia, B.S. Mathematical and Computational Science, Stanford University ‘16 2016 Google Brain Resident
In October 2015 we launched the Google Brain Residency, a 12-month program focused on jumpstarting a career for those interested in machine learning and deep learning research. This program is an opportunity to get hands on experience using the state-of-the-art infrastructure available at Google, and offers the chance to work alongside top researchers within the Google Brain team.
Our first group of residents arrived in June 2016, working with researchers on problems at the forefront of machine learning. The wide array of topics studied by residents reflects the diversity of the residents themselves — some come to the program as new graduates with degrees ranging from BAs to Ph.Ds in computer science to physics and mathematics to biology and neuroscience, while other residents come with years of industry experience under their belts. They all have come with a passion for learning how to conduct machine learning research.
The breadth of research being done by the Google Brain Team along with resident-mentorship pairing flexibility ensures that residents with interests in machine learning algorithms and reinforcement learning, natural language understanding, robotics, neuroscience, genetics and more, are able to find good mentors to help them pursue their ideas and publish interesting work. And just seven months into the program, the Residents are already making an impact in the research field.
An LSTM Cell (Left) and a state of the art RNN Cell found using a neural network (Right). This is an example of a novel architecture found using the approach presented in “Neural Architecture Search with Reinforcement Learning” (B. Zoph and Q. V. Le, submitted to ICLR 2017). This paper uses a neural network to generate novel RNN cell architectures that outperform the widely used LSTM on a variety of different tasks.
The training accuracy for neural networks, colored from black (random chance) to red (high accuracy). Overlaid in white dashed lines are the theoretical predictions showing the boundary between trainable and untrainable networks. (a) Networks with no dropout. (b)-(d) Networks with dropout rates of 0.01, 0.02, 0.06 respectively. This research explores whether theoretical calculations can replace large hyperparameter searches. For more details, read “Deep Information Propagation” (S. S. Schoenholz, J. Gilmer, S. Ganguli, J. Sohl-Dickstein, submitted to ICLR 2017).
Accepted conference papers(Google Brain Residents marked with asterisks)
The diverse and collaborative atmosphere fostered by the Brain team has resulted in a group of researchers making great strides on a wide range of research areas which we are excited to share with the broader community. We look forward to even more innovative research that is yet to be done from our 2016 residents, and are excited for the program to continue into it’s second year!
We are currently accepting applications for the 2017 Google Brain Residency Program. To learn more about the program and to submit your application, visit g.co/brainresidency. Applications close January 13th, 2017.
Posted by Moritz Hardt, Research Scientist, Google Brain Team
As machine learning technology progresses rapidly, there is much interest in understanding its societal impact. A particularly successful branch of machine learning is supervised learning. With enough past data and computational resources, learning algorithms often produce surprisingly effective predictors of future events. To take one hypothetical example: an algorithm could, for example, be used to predict with high accuracy who will pay back their loan. Lenders might then use such a predictor as an aid in deciding who should receive a loan in the first place. Decisions based on machine learning can be both incredibly useful and have a profound impact on our lives.
Even the best predictors make mistakes. Although machine learning aims to minimize the chance of a mistake, how do we prevent certain groups from experiencing a disproportionate share of these mistakes? Consider the case of a group that we have relatively little data on and whose characteristics differ from those of the general population in ways that are relevant to the prediction task. As prediction accuracy is generally correlated with the amount of data available for training, it is likely that incorrect predictions will be more common in this group. A predictor might, for example, end up flagging too many individuals in this group as ‘high risk of default’ even though they pay back their loan. When group membership coincides with a sensitive attribute, such as race, gender, disability, or religion, this situation can lead to unjust or prejudicial outcomes.
Despite the need, a vetted methodology in machine learning for preventing this kind of discrimination based on sensitive attributes has been lacking. A naive approach might require a set of sensitive attributes to be removed from the data before doing anything else with it. This idea of “fairness through unawareness,” however, fails due to the existence of “redundant encodings.” Even if a particular attribute is not present in the data, combinations of other attributes can act as a proxy.
Another common approach, called demographic parity, asks that the prediction must be uncorrelated with the sensitive attribute. This might sound intuitively desirable, but the outcome itself is often correlated with the sensitive attribute. For example, the incidence of heart failure is substantially more common in men than in women. When predicting such a medical condition, it is therefore neither realistic nor desirable to prevent all correlation between the predicted outcome and group membership.
Equal Opportunity Taking these conceptual difficulties into account, we’ve proposed a methodology for measuring and preventing discrimination based on a set of sensitive attributes. Our framework not only helps to scrutinize predictors to discover possible concerns. We also show how to adjust a given predictor so as to strike a better tradeoff between classification accuracy and non-discrimination if need be.
At the heart of our approach is the idea that individuals who qualify for a desirable outcome should have an equal chance of being correctly classified for this outcome. In our fictional loan example, it means the rate of ‘low risk’ predictions among people who actually pay back their loan should not depend on a sensitive attribute like race or gender. We call this principle equality of opportunity in supervised learning.
When implemented, our framework also improves incentives by shifting the cost of poor predictions from the individual to the decision maker, who can respond by investing in improved prediction accuracy. Perfect predictors always satisfy our notion, showing that the central goal of building more accurate predictors is well aligned with the goal of avoiding discrimination.
To explore the ideas in this blog post on your own, our Big Picture team created a beautiful interactive visualization of the different concepts and tradeoffs. So, head on over to their page to learn more.
Once you’ve walked through the demo, please check out the full version of our paper, a joint work with Eric Price (UT Austin) and Nati Srebro (TTI Chicago). We’ll present the paper at this year’s Conference on Neural Information Processing Systems (NIPS) in Barcelona. So, if you’re around, be sure to stop by and chat with one of us.
Our paper is by no means the final word on this important and complex topic. It joins an ongoing conversation with a multidisciplinary focus of research. We hope to inspire future research that will sharpen the discussion of the different achievable tradeoffs surrounding discrimination and machine learning, as well as the development of tools that will help practitioners address these challenges.
This week, Berlin hosts the 2016 Annual Meeting of the Association for Computational Linguistics (ACL 2016), the premier conference of the field of computational linguistics, covering a broad spectrum of diverse research areas that are concerned with computational approaches to natural language. As a leader in Natural Language Processing (NLP) and a Platinum Sponsor of the conference, Google will be on hand to showcase research interests that include syntax, semantics, discourse, conversation, multilingual modeling, sentiment analysis, question answering, summarization, and generally building better learners using labeled and unlabeled data, state-of-the-art modeling, and learning from indirect supervision.
Our systems are used in numerous ways across Google, impacting user experience in search, mobile, apps, ads, translate and more. Our work spans the range of traditional NLP tasks, with general-purpose syntax and semantic algorithms underpinning more specialized systems. Our researchers are experts in natural language processing and machine learning, and combine methodological research with applied science, and our engineers are equally involved in long-term research efforts and driving immediate applications of our technology.
If you’re attending ACL 2016, we hope that you’ll stop by the booth to check out some demos, meet our researchers and discuss projects and opportunities at Google that go into solving interesting problems for billions of people. Learn more about Google research being presented at ACL 2016 below (Googlers highlighted in blue), and visit the Natural Language Understanding Team page at g.co/NLUTeam.
Workshops 1st Workshop on Representation Learning for NLP Keynote Speakers include: Raia Hadsell (Google DeepMind) Workshop Organizers include: Edward Grefenstette (Google DeepMind), Phil Blunsom (Google DeepMind), Karl Moritz Hermann (Google DeepMind) Program Committee members include: Tomáš Kočiský (Google DeepMind), Wang Ling (Google DeepMind), Ankur Parikh (Google), John Platt (Google), Oriol Vinyals (Google DeepMind)
This week, Las Vegas hosts the 2016 Conference on Computer Vision and Pattern Recognition (CVPR 2016), the premier annual computer vision event comprising the main conference and several co-located workshops and short courses. As a leader in computer vision research, Google has a strong presence at CVPR 2016, with many Googlers presenting papers and invited talks at the conference, tutorials and workshops.
We congratulate Google Research Scientist Ce Liu and Google Faculty Advisor Abhinav Gupta, who were selected as this year’s recipients of the PAMI Young Researcher Award for outstanding research contributions within computer vision. We also congratulate Googler Henrik Stewenius for receiving the Longuet-Higgins Prize, a retrospective award that recognizes up to two CVPR papers from ten years ago that have made a significant impact on computer vision research, for his 2006 CVPR paper “Scalable Recognition with a Vocabulary Tree”, co-authored with David Nister.
If you are attending CVPR this year, please stop by our booth and chat with our researchers about the projects and opportunities at Google that go into solving interesting problems for hundreds of millions of people. The Google booth will also showcase sveral recent efforts, including the technology behind Motion Stills and a live demo of neural network-based image compression. Learn more about our research being presented at CVPR 2016 in the list below (Googlers highlighted in blue).
We believe that AI technologies are likely to be overwhelmingly useful and beneficial for humanity. But part of being a responsible steward of any new technology is thinking through potential challenges and how best to address any associated risks. So today we’re publishing a technical paper, Concrete Problems in AI Safety, a collaboration among scientists at Google, OpenAI, Stanford and Berkeley.
While possible AI safety risks have received a lot of public attention, most previous discussion has been very hypothetical and speculative. We believe it’s essential to ground concerns in real machine learning research, and to start developing practical approaches for engineering AI systems that operate safely and reliably.
We’ve outlined five problems we think will be very important as we apply AI in more general circumstances. These are all forward thinking, long-term research questions -- minor issues today, but important to address for future systems:
Avoiding Negative Side Effects: How can we ensure that an AI system will not disturb its environment in negative ways while pursuing its goals, e.g. a cleaning robot knocking over a vase because it can clean faster by doing so?
Avoiding Reward Hacking: How can we avoid gaming of the reward function? For example, we don’t want this cleaning robot simply covering over messes with materials it can’t see through.
Scalable Oversight: How can we efficiently ensure that a given AI system respects aspects of the objective that are too expensive to be frequently evaluated during training? For example, if an AI system gets human feedback as it performs a task, it needs to use that feedback efficiently because asking too often would be annoying.
Safe Exploration: How do we ensure that an AI system doesn’t make exploratory moves with very negative repercussions? For example, maybe a cleaning robot should experiment with mopping strategies, but clearly it shouldn’t try putting a wet mop in an electrical outlet.
Robustness to Distributional Shift: How do we ensure that an AI system recognizes, and behaves robustly, when it’s in an environment very different from its training environment? For example, heuristics learned for a factory workfloor may not be safe enough for an office.
We go into more technical detail in the paper. The machine learning research community has already thought quite a bit about most of these problems and many related issues, but we think there’s a lot more work to be done.
We believe in rigorous, open, cross-institution work on how to build machine learning systems that work as intended. We’re eager to continue our collaborations with other research groups to make positive progress on AI.
We work on an extremely wide variety of machine learning problems that arise from a broad range of applications at Google. One particularly important setting is that of large-scale learning, where we utilize scalable tools and architectures to build machine learning systems that work with large volumes of data that often preclude the use of standard single-machine training algorithms. In doing so, we are able to solve deep scientific problems and engineering challenges, exploring theory as well as application, in areas of language, speech, translation, music, visual processing and more.
As Gold Sponsor, Google has a strong presence at ICML 2016 with many Googlers publishing their research and hosting workshops. If you’re attending, we hope you’ll visit the Google booth and talk with our researchers to learn more about the exciting work, creativity and fun that goes into solving interesting ML problems that impact millions of people. You can also learn more about our research being presented at ICML 2016 in the list below (Googlers highlighted in blue).
ICML 2016 Organizing Committee Area Chairs include: Corinna Cortes, John Blitzer, Maya Gupta, Moritz Hardt, Samy Bengio
Posted by Rami Barends and Alireza Shabani, Quantum Electronics Engineers
One of the key benefits of quantum computing is that it has the potential to solve some of the most complex problems in nature, from physics to chemistry to biology. For example, when attempting to calculate protein folding, or when exploring reaction catalysts and “designer” molecules, one can look at computational challenges as optimization problems, and represent the different configurations of a molecule as an energy landscape in a quantum computer. By letting the system cool, or “anneal”, one finds the lowest energy state in the landscape - the most stable form of the molecule. Thanks to the peculiarities of quantum mechanics, the correct answer simply drops out at the end of the quantum computation. In fact, many tough problems can be dealt with this way, this combination of simplicity and generality makes it appealing.
But finding the lowest energy state in a system is like being put in the Alps, and being told to find the lowest elevation - it’s easy to get stuck in a “local” valley, and not know that there is an even lower point elsewhere. Therefore, we use a different approach: We start with a very simple energy landscape - a flat meadow - and initialize the system of quantum bits (qubits) to represent the known lowest energy point, or “ground state”, in that landscape. We then begin to adjust the simple landscape towards one that represents the problem we are trying to solve - from the smooth meadow to the highly uneven terrain of the Alps. Here’s the fun part: if one evolves the landscape very slowly, the ground state of the qubits also evolves, so that they stay in the ground state of the changing system. This is called “adiabatic quantum computing”, and qubits exploit quantum tunneling to ensure they always find the lowest energy "valley" in the changing system.
While this is great in theory, getting this to work in practice is challenging, as you have to set up the energy landscape using the available qubit interactions. Ideally you’d have multiple interactions going on between all of the qubits, but for a large-scale solver the requirements to accurately keep track of these interactions become enormous. Realistically, the connectivity has to be reduced, but this presents a major limitation for the computational possibilities.
In "Digitized adiabatic quantum computing with a superconducting circuit", published in Nature, we’ve overcome this obstacle by giving quantum annealing a digital twist. With a limited connectivity between qubits you can still construct any of the desired interactions: Whether the interaction is ferromagnetic (the quantum bits prefer an aligned) or antiferromagnetic (anti-aligned orientation), or even defined along an arbitrary different direction, you can make it happen using easy to combine discrete building blocks. In this case, the blocks we use are the logic gates that we've been developing with our superconducting architecture.
Superconducting quantum chip with nine qubits. Each qubit (cross-shaped structures in the center) is connected to its neighbors and individually controlled. Photo credit: Julian Kelly.
The key is controllability. Qubits, like other physical objects in nature, have a resonance frequency, and can be addressed individually with short voltage and current pulses. In our architecture we can steer this frequency, much like you would tune a radio to a broadcast. We can even tune one qubit to the frequency of another one. By moving qubit frequencies to or away from each other, interactions can be turned on or off. The exchange of quantum information resembles a relay race, where the baton can be handed down when the runners meet.
You can see the algorithm in action below. Any problem is encoded as local “directions” we want qubits to point to - like a weathervane pointing into the wind - and interactions, depicted here as links between the balls. We start by aligning all qubits into the same direction, and the interactions between the qubits turned off - this is the simplest ground state of the system. Next, we turn on interactions and change qubit directions to start evolving towards the energy landscape we wish to solve. The algorithmic steps are implemented with many control pulses, illustrating how the problem gets solved in a giant dance of quantum entanglement.
Top: Depiction of the problem, with the gold arrows in the blue balls representing the directions we’d like each qubit to align to, like a weathervane pointing to the wind. The thickness of the link between the balls indicates the strength of the interaction - red denotes a ferromagnetic link, and blue an antiferromagnetic link. Middle: Implementation with qubits (yellow crosses) with control pulses (red) and steering the frequency (vertical direction). Qubits turn blue when there is interaction. The qubits turn green when they are being measured. Bottom: Zoom in of the physical device, showing the corresponding nine qubits (cross-shaped).
To run the adiabatic quantum computation efficiently and design a set of test experiments we teamed up with the QUTIS group at the University of the Basque Country in Bilbao, Spain, led by Prof. E. Solano and Dr. L. Lamata, who are experts in synthesizing digital algorithms. It’s the largest digital algorithm to date, with up to nine qubits and using over one thousand logic gates.
The crucial advantage for the future is that this digital implementation is fully compatible with known quantum error correction techniques, and can therefore be protected from the effects of noise. Otherwise, the noise will set a hard limit, as even the slightest amount can derail the state from following the fragile path to the solution. Since each quantum bit and interaction element can add noise to the system, some of the most important problems are well beyond reach, as they have many degrees of freedom and need a high connectivity. But with error correction, this approach becomes a general-purpose algorithm which can be scaled to an arbitrarily large quantum computer.
Posted by Kurt Thomas and Yuan Niu, Spam & Abuse Research
Every week, over 10 million users encounter harmful websites that deliver malware and scams. Many of these sites are compromised personal blogs or small business pages that have fallen victim due to a weak password or outdated software. Safe Browsing and Google Search protect visitors from dangerous content by displaying browser warnings and labeling search results with ‘this site may harm your computer’. While this helps keep users safe in the moment, the compromised site remains a problem that needs to be fixed.
Unfortunately, many webmasters for compromised sites are unaware anything is amiss. Worse yet, even when they learn of an incident, they may lack the security expertise to take action and address the root cause of compromise. Quoting one webmaster from a survey we conducted, “our daily and weekly backups were both infected” and even after seeking the help of a specialist, after “lots of wasted hours/days” the webmaster abandoned all attempts to restore the site and instead refocused his efforts on “rebuilding the site from scratch”.
In order to find the best way to help webmasters clean-up from compromise, we recently teamed up with the University of California, Berkeley to explore how to quickly contact webmasters and expedite recovery while minimizing the distress involved. We’ve summarized our key lessons below. The full study, which you can read here, was recently presented at the International World Wide Web Conference.
When Google works directly with webmasters during critical moments like security breaches, we can help 75% of webmasters re-secure their content. The whole process takes a median of 3 days. This is a better experience for webmasters and their audience.
How many sites get compromised?
Number of freshly compromised sites Google detects every week.
Over the last year Google detected nearly 800,000 compromised websites—roughly 16,500 new sites every week from around the globe. Visitors to these sites are exposed to low-quality scam content and malware via drive-by downloads. While browser and search warnings help protect visitors from harm, these warnings can at times feel punitive to webmasters who learn only after-the-fact that their site was compromised. To balance the safety of our users with the experience of webmasters, we set out to find the best approach to help webmasters recover from security breaches and ultimately reconnect websites with their audience. Finding the most effective ways to aid webmasters
Getting in touch with webmasters: One of the hardest steps on the road to recovery is first getting in contact with webmasters. We tried three notification channels: email, browser warnings, and search warnings. For webmasters who proactively registered their site with Search Console, we found that email communication led to 75% of webmasters re-securing their pages. When we didn’t know a webmaster’s email address, browser warnings and search warnings helped 54% and 43% of sites clean up respectively.
Providing tips on cleaning up harmful content: Attackers rely on hidden files, easy-to-miss redirects, and remote inclusions to serve scams and malware. This makes clean-up increasingly tricky. When we emailed webmasters, we included tips and samples of exactly which pages contained harmful content. This, combined with expedited notification, helped webmasters clean up 62% faster compared to no tips—usually within 3 days.
Making sure sites stay clean: Once a site is no longer serving harmful content, it’s important to make sure attackers don’t reassert control. We monitored recently cleaned websites and found 12% were compromised again in 30 days. This illustrates the challenge involved in identifying the root cause of a breach versus dealing with the side-effects.
Making security issues less painful for webmasters—and everyone
If you’re a hosting provider or building a service that needs to notify victims of compromise, understand that the entire process is distressing for users. Establish a reliable communication channel before a security incident occurs, make sure to provide victims with clear recovery steps, and promptly reply to inquiries so the process feels helpful, not punitive.
As we work to make the web a safer place, we think it’s critical to empower webmasters and users to make good security decisions. It’s easy for the security community to be pessimistic about incident response being ‘too complex’ for victims, but as our findings demonstrate, even just starting a dialogue can significantly expedite recovery.