Krzysztof Gajos



Krzysztof Gajos

Photo: Fredo Durand

Email: kgajos at
Phone: +1-617-496-1876
Office: Maxwell Dworkin Building, Room 251

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I am an associate professor of Computer Science in the School of Engineering and Applied Sciences at Harvard University. My research interests are in human-computer interaction, artificial intelligence and applied machine learning. The phrase "intelligent interactive systems" describes well many of my interests: I am interested in how intelligent technologies can enable novel ways of interacting with computation, and in the new challenges that human abilities, limitations and preferences create for machine learning algorithms embedded in interactive systems. Together with several students, I have started the Intelligent Interactive Systems Group at Harvard. The main themes in my current research are personalized adaptive accessibility, creativity support tools, interactive machine learning, methodologies for conducting large-scale experiments with online volunteers, and crowdsourcing.

If you wish to see what we do, look at our group's projects page or check out some of our fun experiments on Lab in the Wild.

If you are interested in joining me as a graduate student, please apply through the School of Engineering and Applied Sciences or read the information for prospective graduate students.

Before Harvard

In June 2008, I graduated from University of Washington and I subsequently joined the Adaptive Systems and Interaction group at Microsoft Research for a one year post doc.

While at the University of Washington, I built the SUPPLE system for automatically generating personalized user interfaces. A short video illustrates how SUPPLE can generate user interfaces adapted to people's motor and vision abilities.

In the Fall of 2005, I was visiting faculty at the Ashesi University in Accra, Ghana, where I taught Introduction to Artificial Intelligence.

Before coming to the University of Washington, I spent seven years at MIT where I earned my Bachelors and Masters degrees, and where I also worked for two years as a research scientist managing the operations of the Intelligent Room Project and coordinating some of the activities related to Project Oxygen at the MIT AI Lab (currently part of CSAIL).


Friday, January 9: Our CHI'15 paper on Opportunities for Computer Support of Teamwork in Complex Healthcare is now available online.


Monday, November 3: Our CSCW'15 paper Toward Collaborative Ideation at Scale -- Leveraging Ideas from Others to Generate More Creative and Diverse Ideas" is now available online!

Sunday, November 2: Our Learnersourcing paper for CSCW is now available. Learnersourcing is an approach in which intrinsically motivated learners contribute to a human computation workflow as they naturally engage in a meaningful learning activity. Want to see what this looks like? Check out our Crowdy system for learnersourcing subgoal labels for tutorial videos.

Tuesday, October 14: Our CSCW paper on LabintheWild is ready.

Friday, September 12: At the AAAI Fall Sumposium on Expanding the Boundaries of Health Informatics Using AI, Ofra will reveal our secret plan to use AI to support teamwork for coordinated care of children with complex conditions.

Monday, September 1: We will be presenting three papers at CSCW'15:

  • "Toward Collaborative Ideation at Scale — Leveraging Ideas from Others to Generate More Creative and Diverse Ideas" -- new crowd- and machine learning--powered system to pick out sets of diverse high quality examples of ideas generated by earlier contributors to inspire future contributors. Increases quality and diversity of generated ideas.
  • "Learnersourcing Subgoal Labels for How-to Videos" -- today's learners make tutorial videos even better for future learners by contributing to non-trivial human computation tasks as a byproduct of doing things that they are already motivated to do.
  • "LabintheWild: Conducting Large-Scale Online Experiments With Uncompensated Samples" -- data obtained through LabintheWild are as good as the data collected in traditional lab-based studies.
Final versions of these papers will be online in a few weeks.

Tuesday, August 12: The focus of this year's CS 279 will be social computing and crowd-powered systems. Specifically, we will look at the design and analysis of systems, in which crowds of intrinsically motivated volunteers contribute to meaningful and non-trivial human computation tasks as a byproduct of doing something that they are motivated to do anyway. The course is designed for first year grads from all areas. Advanced undergraduates are also welcome, particularly those who wish to do reserach (or write a thesis) in an area related to Human-Computer Interaction.

Monday, August 11: Juho's work on LectureScape (the paper will be presented at UIST'14) just got nice coverage on It also got mentioned here. There is a video if you want to learn more.

cupcake with two burning birthday candles Monday, July 7: LabintheWild is turning 2!

Sunday, June 29: We have a postdoctoral position available for an education-related project.

Tuesday, June 24: Two of our papers (both lead by Juho Kim) got conditionally accepted to UIST'14: "Data-Driven Interaction Techniques for Improving Navigation of Educational Videos" and "Content-Aware Kinetic Scrolling for Supporting Web Page Navigation". See you in Hawaii!

Tuesday, May 20: Want to learn web programming? Check out Crowdy, a better way to learn from video tutorials. This project is run by our frients at MIT CSAIL.

Thursday, May 15: Ken Nakayama (psychology), Ryan Enos (government) and I received a grant from the Harvard Initiative for Learning and Teaching for integrating online behavioral research modules into the classroom. Essentially, we want to bring the kind of experiential learning (lecture demonstrations, open-ended labs) that is common in natural sciences to education in psychology, social sciences and HCI.

Sunday, April 27: Steve presented his work on Organic Peer Assessment at the Learning Innovation at Scale workshop at CHI.

Friday, February 7: Our paper on Crowdsourcing Step-by-Step Information Extraction to Enhance Existing How-to Videos will be recognized with an Honorable Mention at CHI'14.

Friday, January 24: The final version of our paper on Understanding In-Video Dropouts and Interaction Peaks in Online Lecture Videos (to appear at Learning at Scale conference) is now available.

Sunday, January 19: Curio and Lab in the Wild are featured in an article on Popular Science in the current issue of Harvard Magazine.

Friday, January 17: The final versions of our CHI'14 papers are now available:

Friday, January 17: The final versions of our IUI'14 papers are now available:

Friday, December 20: Our paper on Understanding In-Video Dropouts and Interaction Peaks in Online Lecture Videos led by Juho Kim has been accepted to Learning at Scale.

Monday, December 9: Two of our papers got accepted to CHI: "Quantifying Visual Preferences Around the World" led by Katharina Reinecke and "Crowdsourcing Step-by-Step Information Extraction to Enhance Existing How-to Videos" led by Juho Kim.

Thursday, December 5: Our two papers got accepted to ACM IUI: "Adaptive Click-and-Cross: Adapting to Both Abilities and Task Improves Performance of Users With Impaired Dexterity" led by Louis Li and "Active Learning of High-Level Knobs for Synthesis with Gaussian Processes" led by Anna Huang.

Thursday, November 14: Today we ran a panel on Taking Research Out Into the Wild. Main message: engaging broader publics over the internet (either as participants or as collaborators) makes answering entirely new kinds of questions possible and it does not require superhuman abilities or resources.

Sunday, October 27: In collaboration with the Center for Research on Computation and Society (CRCS), we are now accepting applications for 1- or 2-year Postdoctoral Fellowships. Consider applying even if you are currently seeking a faculty position. Many schools will let you defer your faculty position for a year and a Fellowship at CRCS is a great way to develop your research agenda and to expand your research network.

Friday, October 25: Our team (led by Mary Regan at UMD School of Nursing) received an R01 NIH grant to study the behavioral and nutritional factors impacting pre-term birth. A key technical enabler of this project is a mechanism, based on our PlateMate system, for scalable nutritional analysis, which will make it possible to track the nutritional intake of 400 pregnant women for several months each.

Adaptive Click-and-Cross Monday, October 21: Louis Li presented a poster on his work on Adaptive Click-and-Cross at the ACM ASSETS conference. Adaptive Click-and-Cross combines several adaptive mechanisms (which were previously studied in isolation) to improve the efficiency of computer access for people with impaired dexterity.

Wednesday, October 16: Our paper reporting on an Evaluation of filesystem provenance visualization tools was presented today at IEEE InfoVis.

Saturday, October 12: The first results from the age guessing experiment: 17-year olds are the most efficient clickers. Past the age of 25, we all get slower at a steady rate for the rest of our lives. Read more...

TiiS Friday, October 11: I have joined Tony Jameson as a co-Editor in Chief of the ACM Transactions on Interative Intelligent Systems (TiiS). I am helping fill the unfillable gap left by the passing of John Riedl, who was one of the two founding EICs of the journal. TiiS aims to be the primary venue for research that bridges HCI and AI (both broadly construed). Please consider submitting.

Sunday, Sept 22: Reminder: CrowdCamp applications are due on Sept 25! Next CrowdCamp (a two-day hack-a-thon for prototyping novel crowd-powered ideas) will take place at HCOMP'13 and will be lead by a great team: Lydia Childton (UW), Juho Kim (MIT) and Pao Siangliulue (Harvard).

Sunday, September 8: At HCOMP 2013, we will present a demo of Curio, a crowdsourcing platform that connects interested citizens with researchers to help answer important questions in the sciences and humanities. Read the abstract.

Monday, September 1: Detailed timeline is now available for CS 279: Topics in Human-Computer Interaction Research. The course is designed for first year grads from all areas and for dvanced undergrads, particularly those who wish to do reserach (or write a thesis) in an area related to Human-Computer Interaction. Special focus this year is on human-computer interaction research at scale, i.e., large-scale online experiments, crowdsourcing, and social media analysis. Class will meet on Tuesdays and Thursdays, 10-11:30am, in Pierce 100F.

Monday, July 22: on Monday, July 15, John Riedl passed away. John was best known for his pioneering work on recommender systems and social computing. I found John's research particularly admirable because it combined exciting technical contributions with deep insights into social psychology, thus merging the technical and the human in ways that were rigorous, informative and inspiring. Several years ago, John became the founding editor of the ACM Transactions on Interactive Intelligent Systems (TiiS), a flagship journal for research combining advances in AI and Machine Learning with rigorous insights into Human-Computer Interaction.

Steven Snyder wrote a more extensive piece in memory of John. If you would like to honor John's memory in a more tangible way, you can donate to a scholarship fund set up by University of Minnesota in John's memory.

Saturday, July 20: At long last, we have published a data set to accompany our 2011 PlateMate paper. The data set contains 16 out of the 18 images we used to evaluate PlateMate's accuracy. The data set also includes the ground truth nutritional info for each photograph, expert estimates, as well as PlateMate's estimates.

Monday, June 24: We are gearing up to launch Curio, a crowdsourcing platform that connects interested citizens with researchers to help answer important questions in the sciences and humanities. Sign up now to receive an early access invitation!

Friday, May 31: More than 500,000 people have participated in experiments on Lab in the Wild.

Friday, April 19: More than 100,000 people have participated in experiments on Lab in the Wild.

Sunday, March 10: Our SPRWeb paper will receive a best paper award at CHI 2013 and our paper on predicting first impressions of web site aesthetics will get an honorable mention. Both will be presented in the Aesthetics and the Web session on Wednesday morning.

Tuesday, March 5: A few days ago at CrowdCamp, we have experimented with new ways to elicit creative ideas from crowds by combining techniques from Design, Improv Theater, Crowdsourcing, and AI. Here's our story.

Thursday, February 14: I was selected as one of the 2013 Sloan Research Fellows. Big thanks to my students, postodcs, and colleagues.

Current and Recent Projects