The Noisy Channel


Gone Medium

January 26th, 2016 by Daniel Tunkelang

I’ve recently switched platforms again. You can now find my posts on Medium.

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The Noisy Channel Has Moved To LinkedIn

March 7th, 2013 by Daniel Tunkelang

If you’re reading this, then you’re probably interested in my current writing. You can find my latest posts on my LinkedIn author page.


Onward, Upward, and [In]ward

December 29th, 2012 by Daniel Tunkelang

It’s that time — the end of another great year. It’s been a phenomenal year for LinkedIn, for my amazing team of data scientists, and for me personally.

The end of year is also an exciting time of transition. I enter 2013 thinking about my daughter starting kindergarten, the house awaiting me after a lifetime of apartment dwelling, and of course all the great things my team is setting out to accomplish.

One of those transitions concerns this blog. About a month ago, I started posting on LinkedIn as an “influencer” — one of a couple of hundred people privileged to use LinkedIn as a native publishing platform. The thousands of people following me there and engaging with my content have convinced me to go all in.

I will keep this site up with the hundreds of posts I’ve published over the past 4+ years, but I’ll put The Noisy Channel on mute for the foreseeable future. So, whether you’re a long-time reader or someone who just got here, I hope you’ll follow me on LinkedIn and read my posts there.

I’m excited about the upcoming year. There’s lots of great stuff on my team’s roadmap, as well as fun opportunities to participate in conferences. Hopefully I’ll see some of you at the Stanford Conference on Computational Social Science and at the O’Reilly Strata Conference. But most of all I hope to continue engaging with all of you offline and online.

Happy New Year, and see you on LinkedIn!


Continuing to Post on LinkedIn

December 4th, 2012 by Daniel Tunkelang

I just posted another pair of articles on LinkedIn:

I’ll continue to use The Noisy Channel as a personal blog, but I’ll be focusing my publishing efforts on LinkedIn. Hope you’ll follow me there!


Follow Me on LinkedIn!

November 20th, 2012 by Daniel Tunkelang

I’ve recently started posting on LinkedIn as part of LinkedIn’s thought leadership program.

My first two posts as an “influencer” are a bit meta:

I’m curious to hear what you think — both of the content and of the platform. I have no immediate intention to migrate the The Noisy Channel to LinkedIn, but I’m very excited by the initial feedback I’ve gotten for these posts.

Meanwhile, I encourage you to follow me on LinkedIn!

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CIKM 2012: Notes from a Conference in Paradise

November 12th, 2012 by Daniel Tunkelang

The moment I learned that CIKM 2012 would be held in Maui, I knew I had to be there. Having co-organized the CIKM 2011 industry event, I had enough karma to be invited as part of this year’s industry event, representing LinkedIn.


I arrived in Maui on Sunday, October 28th, fortunate to miss the “pseunami” warnings prompted by an earthquake off the Canadian coast. And even more fortunate to be thousands of miles away from Hurricane Sandy.

Monday, I attended the Workshop on Data-Driven User Behavioral Modeling and Mining from Social Media. The topics within this area were diverse: they included Pinterest users, resume-job matching (unfortunately without the benefit of LinkedIn data), and street harassment stories reported via Project Hollaback.

But ironically in this workshop — and throughout the conference — there was more use of Twitter data than of Twitter itself. Most of the tweets using the #cikm2012 hashtag were my own.


Tuesday opened with a welcome that included statistics showing how far CIKM has come as a top-tier international conference. There were 1,088 submissions this year! But the highlight of the opening was program co-chair Guy Lebanon demoing software to “improve” paper reviews. It was hilarious, if a bit close to home: the automatically generated reviews looked a lot like those generated by allegedly human reviewers.

We then proceeded to a keynote by Yahoo! Research VP Ricardo Baeza-Yates entitled “User Engagement: The Network Effect Matters!” The title was a bit confusing: it wasn’t about the conventional “network effect“, but rather about user engagement across a network of sites like those owned by Yahoo. He talked about different ways to measure user engagement, and noted that off-site (or, rather, off-network) links ultimately improve users’ downstream engagement. He also observed that style attributes outperform content attributes as predictors of user engagement. Lots of fascinating observations, but I’m curious how well they generalize beyond Yahoo.

I spent the rest of the day making tough choices among the various parallel sessions, starting with the morning session on information retrieval evaluation. Some nuggets from that session: captions and other surface features introduce significant evaluation bias; assessors have poor agreement when evaluating relevance in eDiscovery contexts; and system evaluation improves when it models user differences.

After lunch, I attended a session on web search. Some themes from that session: neighborhood-based methods are effective, whether the neighborhoods are based on document or user similarity; entities and structure are increasingly important for web search. After the coffee break, I went to the social networks session. Topics there included social contagion, online question answering, and social network data anonymization. The talks wrapped up just in time for us to watch the daily cliff diving ceremony before heading to the poster session.


Wednesday opened with a keynote by CMU professor Wllliam Cohen on “Learning Similarity Measures based on Random Walks in Graphs“. He described the framework and techniques that he and his colleagues used to build NELL (“Never-Ending Language Learning”). The keynote was pretty dense, but there are lots of papers available on the NELL publications page.

Then back to choosing among parallel sessions. Although I was tempted by the recommender systems session featuring presentations by my LinkedIn colleagues Mitul Tiwari and Bee-Chung Chen, I instead attended the session on ads and products. Two take-aways from that session: ad targeting benefits from explicit identification of user interests; influence maximization can be modeled adversarially as a two-player game.

After lunch, I attended the session on formal retrieval models and learning to rank. I most enjoyed the two talks by Oren Kurland that focused on query performance prediction. In particular, he offered a comprehensive probabilistic prediction framework that unifies most of the previously proposed prediction methods using a common formal basis. The session also included a deep dive into aspects of the IBM Watson question-answering system.

After the coffee break, I headed to another session on web search — one of my favorite sessions of the conference. There was a talk on query segmentation, a topic responsible for my most popular blog post. Also a great talk on identifying good abandonment, a problem I’ve been interesting ever since hearing about it at SIGIR 2010. Another talk about learning from search logs: generalizing from click entropy to “click pattern entropy” to analyze query ambiguity. And a talk on modeling domain-dependent query reformulation as machine translation using a pseudo-parallel corpus. All in all, a great session packed with practical content.

Then came a purely social evening. The conference reception was a luau, complete with kalua pig, mai tais, hula, and of course poi. Certainly my most memorable conference banquet. I didn’t take pictures, but I recommend Craig Stanfill‘s photos on Flickr.

And then some of us went to downtown Lahaina to see how the locals (and tourists) celebrate Halloween. Much as I missed spending Halloween with my family, I had a blast!


Thursday began with the last conference keynote: University of Kansas provost Jeffrey Vitter on “Compressed Data Structures with Relevance“. Like the previous keynotes, it was fairly dense, and I suggest you read the papers cited in his abstract if you’re interested in the technical details of how to search for query patterns in massive document collections.

Then came my main reason for attending the conference: the industry event. As seems to have become a pattern at information retrieval conferences, the industry event dominated the other parallel sessions, drawing a standing-room only crowd.

The event started with eBay VP of Research Eric Brill talking about “Having A Great Career in Research”. Unusual in a conference talk, he offered personal and practical advice to students on how to focus their passion and effort towards a happy and successful career. It reminded me of my blog post about dream, fit, and passion, and I hope students took it to heart.

IBM researcher David Carmel gave a talk entitled “Is This Entity Relevant to Your Needs?”. Noting that 71% of web search queries contain named entities (people, places, organizations), he advocated a probabilistic ranking approach to entity-oriented search that ranks retrieved entities according to amount and quality of supporting evidence.

Microsoft Technical Fellow (and former Yahoo! Fellow) Raghu Ramakrishnan talked about “The Future of Information Discovery and Search: Content Optimization, Interactivity, Semantics, and Social Networks”. He packed in a lot of nice material, most of which was from his tenure at Yahoo. He included a nice explanation of explore/exploit, which was also a reminder of how lucky we are at LinkedIn to have hired his former Yahoo colleague Deepak Agarwal.

After lunch, WalmartLabs Chief Scientist AnHai Doan gave a talk entitled “Social Media, Data Integration, and Human Computation”, in which he described constructing a “social genome” by mining social data, connecting it to web data, representing the combined information in a knowledge base. If you’re interested in more details, he’ll be giving an extended version of that talk at LinkedIn on November 29th!

Tencent Research Director Chao Liu talked about “Question Answering through Tencent Open Platform”. Beyond giving a great overview of one of the world’s largest internet platforms, he delivered great self-deprecating lines like “The name is ten cents, and the search engine is soso“.

I spoke next about LinkedIn‘s “Data By The People, For The People“. Given that the talk was right after Halloween and just before the presidential elections, I thought it appropriate to choose a title that would have appealed to one of America’s most distinguished presidents and vampire hunters. If you’re curious to learn more about data science and engineering at LinkedIn (including the publications I cited in my talk), check out

Groupon Director of Research Rajesh Parekh talked about “Leveraging Data to Power Local Commerce”. He focused on a key problem Groupon faces: determining and optimal category mix for each local market. He described how they approach this problem using portfolio theory.

After a coffee break, Adobe Chief Software Architect Tom Malloy talked about “Revolutionizing Digital Marketing with Big Data Analytics”. Apache Pig co-creator — and now Google researcher — Christopher Olston talked about work he did at Yahoo on “Programming and Debugging Large-Scale Data Processing Workflows”. Finally, Microsoft Distinguished Engineer Xuedong (“XD”) Huang gave a talk entitled “From HyperText to HyperTEC”, in which he woke up the audience by having us all participate in the “Bing it On” challenge.


All in all, CIKM 2012 was a great conference in an idyllic setting. Holding the conference in Maui might have been a bit distracting, but the desirability of the location also ensure a high-quality program.

My main complaint is that I don’t like parallel sessions — especially when the topics overlap significantly (e.g., web search sessions competed with those on ranking and recommendations). I’m also not convinced that talks have to be 25 minutes long. Perhaps the conference could more to a format of shorter talks and at least reduce the number of parallel sessions. It would also be great to see more opportunity for interaction — the coffee breaks always felt too short. For more of my thoughts on reforming academic conferences, see my 2009 blog post on the subject.

I also wish more attendees would embrace social media. It’s ironic that researchers who depend so heavily on social media data (especially Twitter) don’t engage in it personally. While I’m honored to have been the conference’s unofficial tweeter (see this visualization of the #cikm2012 tweets), I would have liked to see more attendees engage in a public online conversation. Hopefully others will at least blog about the conference.

But these are quibbles. CIKM continues to be an outstanding conference, and I’m very excited it’s coming to the Bay Area next year. See you at CIKM 2013!


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Data By The People, For The People

November 11th, 2012 by Daniel Tunkelang

I was fortunate this year not only to be able to attend the 21st ACM International Conference on Information and Knowledge Management (CIKM 2012) in Maui, but also to be invited as part of this year’s industry event, representing LinkedIn.

Above are the slides I presented on “Data By The People, For The People“. Enjoy!


LinkedIn at CIKM 2012

October 26th, 2012 by Daniel Tunkelang

Last year, I had the pleasure of co-organizing the CIKM 2011 Industry Event in Glasgow. This year, I’m honored to be part of the CIKM 2012 Industry Event program, along with top industry researchers from Adobe, eBay, Google, Groupon, IBM, Microsoft, Tencent, and Walmart Labs. I’ll be giving a talk on “Data By The People, For The People“.

I’m also thrilled to be joined by my colleague Mitul Tiwari, who will be presenting a paper on “Metaphor: A System for Related Search Recommendations“, work that he did with Azarias Reda, Yubin Park, Christian Posse, and Sam Shah.

Finally, we’ll be representing Manuel Gomez-Rodriguez and Monica Rogati at the poster session, presenting their work on “Bridging Offline and Online Social Graph Dynamics“.

If you’re attending CIKM, please make sure to say hi to me and Mitul. We’d be delighted to talk to you about the work that we and our colleagues are doing. Our data team also has a site showcasing our team, our publications, and some of the projects we can discuss publicly. And, of course, we’re hiring!

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HCIR 2012: A Personal Report

October 8th, 2012 by Daniel Tunkelang

Human-computer information retrieval (HCIR) is the study of information retrieval techniques that integrate human intelligence and algorithmic search to help people explore, understand, and use information. Since 2007, the HCIR Symposium (previously known as the HCIR Workshop) has provided a venue for the theoretical and practical study of HCIR. We even inspired an EuroHCIR workshop across the pond that started in 2011 and is going strong.


The Sixth Symposium on Human-Computer Interaction and Information Retrieval (HCIR 2012) took place on October 4th and 5th at IBM Research in Cambridge, MA. The 75 attendees represented a cross-section of HCIR research and practice. Over a third of the attendees were from industry — including startups and large technology firms. We had a similar diversity of sponsors, benefiting from the generosity of FXPAL, IBM Research, LinkedIn, Mendeley, Microsoft Research, MIT CSAIL, and Oracle. And we had participants from 6 countries: Canada, Germany, Israel, New Zealand, Switzerland, and the United States.


We started the Symposium with a keynote from UC Berkeley professor Marti Hearst, a pioneer in the area of search user interfaces, as well as a prominent researcher of information visualization, natural language processing, and social media analysis. Marti set the tone for the symposium with a visionary keynote that she entitled her “Halloween Cauldron of Ideas for Research”.

She started by talking about the unaddressed seams of sensemaking, reminding us that information seeking is only one part of an overall sensemaking process. She used the challenge of saving and personally organizing search results as an example of a neglected but crucial part of a search interface.

She then challenged us to think about how audio could be used in search interfaces. She cited a study showing that programmers comment their code better when the commenting interface uses speech rather than the keyboard. She then challenged us to consider how auditory notification or feedback could enhance the search experience.

Finally, she presented the idea of “radical collaboration”, offering as an example the use of Mechanical Turk to crowdsource vacation planning. The plans were tested by real tourists, who were delighted with the results.

Marti’s keynote was not only insightful and entertaining (one of her slides featured brain cupcakes!), but notable in how much she engaged all of us in discussion throughout her presentation. This approach was especially appropriate for an HCIR Symposium, given our emphasis on human interaction. For more detail about the keynote, I recommend Gene Golovchinsky’s summary.

Short Paper Presentations

After a coffee break, we had a session devoted to 5 short papers. Each presenter had 10 minutes: 5 minutes to present and 5 minutes for discussion.

The short presentation format was extremely effective, encouraging presenters to communicate their ideas efficiently and leaving ample time for discussion.

Posters and Demos

As in previous years, we followed lunch with a vibrant session for posters and demos. Some of the more popular poster themes included question answering, task difficulty, and collaborative information seeking. Here is the full list of poster / demo presentations:

Full Paper Presentations

The full paper presentations were split into two sessions, the first held on the 4th and the second held on the 5th. Each presentation slot was 30 minutes. The full papers will be made available soon through the ACM Digital Library.

  • University of Magdeburg student Marcus Nitsche presented “Knowledge Journey: A Web Search Interface for Young Users”, joint work with Tatiana Gossen and Andreas Nürnberger. The authors performed a study in which they found that children liked having personalized avatars that offer guidance, a wheel-shaped browsing menu, and a coverflow-style results presentation. It will be interesting to see how their study holds up in larger-scale user studies, and whether adults like some of these interface elements too.
  • Oregon State University professor Carlos Jensen presented “Leyline: Provenance-Based Search Using a Graphical Sketchpad”, joint work with Seyedsoroush Ghorashi. I was intrigued to see a search approach focused entirely on provenance — that is, the history of a document’s ownership and transformations. I’m particularly curious about this area, since I’m a committee member for Aleatha Parker-Wood, who is pursuing a dissertation on “Making Sense of File Systems Through Provenance and Rich Metadata“.
  • University of Waterloo professor Mark Smucker presented joint work with Charlie Clarke on “Modeling User Variance in Time-Biased Gain”. Their simulation-based approach produced distributions of gain that agree with distributions produced by real users. By emphasizing the effect size of differences, their approach could help uncover how much the performance differences among systems matter to real users.
  • Finally, University of North Carolina at Chapel Hill professor Barbara Wildemuth and University of British Columbia professor Luanne Freund delivered a highly interactive presentation on “Assigning Search Tasks Designed to Elicit Exploratory Search Behaviors”. They performed an extensive survey of information exploration literature to identify concepts that authors have used to characterize exploratory search tasks. They tested examples on the audience to see how well we agreed with their characterization and with one another.

HCIR Challenge

With Friday morning came the most anticipated event of the Symposium: the HCIR Challenge. The Challenge is now in its third year: the 2010 Challenge focused on historical exploration of news using the New York Times Annotated Corpus; the 2011 Challenge focused on the problem of information availability using the CiteSeer digital library of scientific literature.

This year, we turned to the problem of people and expertise finding, a topic of obvious personal interest. We are grateful to Mendeley for providing this year’s corpus: a database of over a million researcher profiles with associated metadata including published papers, academic status, disciplines, awards, and more taken from Mendeley’s network of 1.6M+ researchers and 180M+ academic documents.

We asked participants to build systems that could perform three kinds of tasks:

  1. Hiring. Given a job description, produce a set of suitable candidates for the position.
  2. Assembling a Conference Program. Given a conference’s past history, produce a set of suitable candidates for keynotes, program committee members, etc. for the conference.
  3. Finding People to deliver Patent Research or Expert Testimony. Given a patent, produce a set of suitable candidates who could deliver relevant research or expert testimony for use in a trial. These people can be further segmented, e.g., students and other practitioners might be good at the research, while more senior experts might be more credible in high-stakes litigation.

Each of the 5 teams was given 30 minutes to present.

THE WINNER: Virtu! The competition was fierce, but Virtu stood out for the compelling approach it took to offering users control over the expert-finding process. Congratulations to Luanne, Kristof, and their colleagues for their outstanding work and well-deserved honor.


After we wrapped up the first day of the Symposium, we walked over to the nearby Technique, a restaurant in the Athenaeum Press building (home to two of Endeca’s offices in our early years) where students of Le Cordon Bleu practice their culinary skills. I’m no master chef, but I certain hope these students earned excellent grades for their performance. We enjoyed a delightful sampling of wines, appetizers, main courses, and desserts.


HCIR has been getting better every year, and this year was no exception. Many attendees in previous years had felt that the one-day format made the event feel rushed, and expanding to a second day took off much of the time pressure. We had ample opportunity for discussion, during the presentations as well as at the coffee breaks and reception. Finally, the Challenge was our best yet, eliciting extraordinary results from the five participating teams.

I’m proud of how far we’ve taken HCIR in these six years, and especially grateful to co-organizers Robert CapraGene GolovchinskyBill KulesCatherine Smith, and Ryen White.

Time to start thinking about HCIR 2013!


Office Hours at Cambridge Brewing Company

October 1st, 2012 by Daniel Tunkelang

I’ll be in Cambridge, MA this Thursday and Friday for the Sixth Symposium on Human-Computer Interaction and Information Retrieval (HCIR 2012). Hope to see many of you there!

But I’ll also have a few hours on Wednesday evening to meet people informally. If you’re interested in learning more about LinkedIn, data science or anything else, then hop over to the  Cambridge Brewing Company on Wednesday, October 3rd. I should be there by 5pm, assuming my flight arrives on time, and I’ll plan to stay there though dinner. I’m pretty easy to contact, so feel free to reach out to me through the usual channels.

MIT and Harvard students and faculty are especially welcome!


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