Friday, April 15, 2011

Deadline for HCOMP 2011 extended: Submission due on April 29th

Due to a significant number of requests, and a number of conflicts with other conferences and workshops, we decided to extend the submission deadline for HCOMP 2011. The new deadline is April 29th.

If you want to know more, you can see the call for papers and workshop announcement.

Video from NYC Crowdsourcing Meetup

On April 13th, we hosted at NYU Stern the NYC Crowdsourcing Meetup. For those who missed it, you can now download an audio-only podcast version, see the online video, or watch the video from the event together with the slide presentations:

The speakers at the event:
  • John Horton, Staff Economist of oDesk. John talked on issues of matching employers with contractors in an online marketplace. Specifically he described mechanisms for forcing contractors to give an accurate description of their skills, avoiding issues of over-tagging a profile with irrelevant keywords or over-claiming qualifications.
  • Amanda Michel, Director of Distributed Reporting at ProPublica. Amanda talked about the crowdsourcing efforts of ProPublica, and how they use the crowd to enable better journalistic investigation of topics they are researching. At some point during the presentation, Amanda quoted from one of their studies "ProPublica pulled a random sample of 520 of the roughly 6,000 approved projects to examine stimulus progress around the country. That sample is large enough to estimate national patterns with a margin of error of plus or minus 4.5 percentage points." Honestly, a tear came down my eye when I compared that with the corresponding practices of Greek newsrooms that typically operate with samples of n=1 or n=0.
  • Todd Carter, CEO and Co-Founder of Tagasauris. Todd described Tagasauris, a system for annotating and tagging media files. Todd described the annotation effort for Magnum Photos, (sample photos in their collection include the Afghan refugee girl, Merilyn Monroe on top of the vent, and many other iconic photos). A highlight was the discovery of a "lost" set of images from the shooting of the movie "American Graffiti". These images, shot by Dennis Stock, were in the Magnum archive but were not possible to find as they were lacking any tags and description. After the annotation effort from Tagasauris, the lost set of photos were re-discovered.
  • Panos Ipeirotis, representing AdSafe Media. I talked about our efforts in AdSafe, on using crowdsourcing in order to create machine learning systems for classifying web pages.
It was a lively and successful event. If there is enough interest and participants, I think this is an event that can be repeated periodically.

Sunday, April 10, 2011

NYC Crowdsourcing Meetup: April 13th, 6.30pm

Join us for its first ever New York City Crowdsourcing meetup hosted by NYU and sponsored by CrowdFlower:

Pizza, beer, and thought provoking conversation about the future of work. Come listen, ask, and debate how crowdsourcing is changing everything from philanthropy and urban planing to creative design and enterprise solutions.

Confirmed Speakers:

  • Lukas Biewald, CEO and Co-Founder of CrowdFlower
  • Todd Carter, CEO and Co-Founder of Tagasauris
  • John Horton, Chief Economist of oDesk
  • Panos Ipeirotis, Associate Professor at Stern School of Business, NYU
  • Amanda Michel, Director of Distributed Reporting at ProPublica
  • Bartek Ringwelski, CEO and Co-Founder of SkillSlate
  • Trebor Scholz, Associate Professor in Media & Culture at The New School University

Tuesday, April 5, 2011

Tutorial on Crowdsourcing and Human Computation

Last week, together with Praveen Paritosh from Google, we presented a 6-hour tutorial at the WWW 2011 conference, on crowdsourcing and human computation. The title of the tutorial was "Managing Crowdsourced Human Computation".

My slides from the tutorial are available now on Slideshare:

Once Praveen gets clearance from Google, we will post his slides as well.

Judging from all the crap that I get to review lately, I was getting pessimistic about the quality of research on crowdsourcing. However, while preparing the tutorial, I realized the massive amount of high-quality research that is being published. We had 6 hours for the tutorial, and we did not have enough time to cover many really interesting papers. I had to refer people to other, more "specialized" tutorials (e.g., on linguistic annotation, on search relevance, etc), which I mention at the end of the slides.

Special thanks go to my PhD student, Jing Wang, for her slides on market design, Matt Lease for his excellent list of pointers for crowdsourcing resources, Omar Alonso for his tutorial slides on crowdsourcing for search relevance, Alex Quinn and Ben Bederson for their survey on human computation, and Winter Mason for sharing his slides from his CSDM keynote. And all the other researchers for making crowdsourcing and human computation an exciting field for research!

Last but not least: Luis von Ahn with Edith Law will be presenting another tutorial on human computation during AAAI, in San Francisco on August 8th. We will be organizing the HCOMP 2011 workshop in conjunction with AAAI as well! The submission deadline is April 22nd! Do not forget to submit!

An ingenious application of crowdsourcing: Fix reviews' grammar, improve sales

I have been doing research on the economic impact of product reviews for a while. One thing that we have noticed is that the quality of the reviews can have an impact on product sales, independently of the polarity of the review.

High-quality reviews improve product sales

A well-written review tends to inspire confidence about the product, even if the review is negative. Typically, such reviews are perceived as objective and thorough. If we have a high-quality negative review this may serve as a guarantee that the negative aspects of the product are not that bad after all. For example, a negative review, such as "horrible battery life... in my tests battery lasts barely longer than 24 hours," may be perceived as positive by other customers that consider a 24-hour battery life to be more than sufficient.

In our recent (award-winning) WWW2011 paper "Towards a Theory Model for Product Search" (with Beibei Li and Anindya Ghose), we noticed that demand for a hotel increases if the reviews on TripAdvisor and Travelocity are well-written, without spelling errors; this holds no matter if the review is positive or negative. In our TKDE paper "Estimating the Helpfulness and Economic Impact of Product Reviews: Mining Text and Reviewer Characteristics"  (with Anindya Ghose), we observed similar trends for products sold and reviewed on

And what can we do knowing this?

Being in a business school, these findings were considered informative but not deeply interesting. Do not forget, the focus of researchers in business schools is centered on causality and on policy-making. Yes, we now know that it is important for the reviews to be well-written and informative, if we want the product to sell well. But if we cannot do anything about this, it is not deeply interesting. It is almost like knowing that during the cold months the demand for summer resorts drops!

But here comes the twist...

The crowdsourcing solution

Last week, over drinks during the WWW conference, I learned about a fascinating application of crowdsourcing that attacked exactly this issue.

An online retailer noticed that, indeed, products with high-quality reviews are selling well. So, they decided to take action. The retailer used Amazon Mechanical Turk to improve the quality of the reviews posted on its own website. Using the Find-Fix-Verify pattern, the retailed used Mechanical Turk to examine millions of product reviews. (Here are the archived versions of the HITs: Find, Fix, Verify. And if you have not figured out the firm name by now, the retailer is Zappos.) For the reviews with mistakes, they fixed the spelling and grammar errors! Thus they effectively improved the quality of the reviews on their website. And, correspondingly, they improved the demand for their products.

For the curious readers, Zappos has been doing this at least since April of 2009, which means that they were doing it even before being bought by Amazon.

While I do not know the exact revenue improvement, I was told that it was substantial. Given that Zappos spent at least 10 cents per review, and that they examined approximately 5 million reviews, this is an expense of a few hundred thousand dollars. (My archive on MTurk-Tracker kind of confirms these numbers.) So, the expected revenue improvement should have been at least a few million dollars for this exercise to make sense.

Ethical? Notice that they are not fixing the polarity or the content of the reviews. They just change the language to be correct and error-free. I can see the counter-argument that the writing style allows us to judge if the review is serious or not. So, artificially improving the writing style may be considered as interference with the perceived objectivity of the user-generated reviews. I still consider it fine to change the grammar, from the ethics point of view.

But is it ingenious? A resounding yes! It is one of these solutions that is sitting in front of you but you just cannot see it. And this is what makes it ingenious.