Jennifer Widom

From 100 Students to 100,000

Online Education

Typically I teach around 100 students per year in my introductory database course. This past fall my enrollment was a whopping 60,000. Admittedly, only 25,000 of them chose to submit assignments, and a mere 6500 achieved a strong final score. But even with 6500 students, I more than quadrupled the total number of students I’ve taught in my entire 18-year academic career.

The story begins a couple of years earlier, when Stanford computer science faculty started thinking about shaking up the way we teach. We were tired of delivering the same lectures year after year, often to a half-empty classroom because our classes were being videotaped. (The primary purpose of the videotaping is for Stanford’s Center for Professional Development, but the biggest effect is that many Stanford students skip lectures and watch them later online.) Why not “purpose-build” better videos: shorter, topic-specific segments, punctuated with in-video quizzes to let watchers check their understanding? Then class time could be made more enticing for students and instructor alike, with interactive activities, advanced or exotic topics, and guest speakers. This “flipped classroom” idea was evangelized in the Stanford C.S. department by Daphne Koller; I was one of the early adopters, creating my videos during the first few months of 2011. Recording was a low-tech affair, involving a computer, Cintiq tablet, cheap webcam and microphone, Camtasia software, and a teaching assistant to help with editing.

I put my videos online for the public, and soon realized that with a little extra work, I could make available what amounted to an entire course. With further help from the teaching assistant, I added slides (annotated as lecture notes, and unannotated for teaching use by others), demo scripts, pointers to textbook readings and other course materials, a comprehensive suite of written and programming exercises, and quick-guides for relevant software. The site got a reasonable amount of traffic, but the turning point came when my colleague Sebastian Thrun decided to open up his fall 2011 introductory artificial intelligence course to the world. After one email announcement promising a free online version of the Stanford AI course, including automatically-graded weekly assignments and a “statement of accomplishment” upon completion, Sebastian’s public course garnered tens of thousands of sign-ups within a week.

Having already prepared lots of materials, I jumped on the free-to-the-world bandwagon, as did my colleague Andrew Ng with his machine learning course. What transpired over the next ten weeks was one of the most rewarding things I’ve done in my life. The sign-ups poured in, and soon the “Q&A Forum” was buzzing with activity. The fact that I had a lot of materials ready before the course started turned out to be a bit deceptive—for ten weeks I worked nearly full-time on the course (never mind my other job as department chair, much less my research program), in part because there was a lot to do, but mostly because there was a lot I could do to make it even better, and I was having a grand time.

In addition to the video lectures, in-video quizzes, course materials, and self-guided exercises, I added two very popular components: quizzes that generate different combinations of correct and incorrect answers each time they’re launched (using technology pioneered a decade ago by my colleague Jeff Ullman in his Gradiance system), and interactive workbenches for topics ranging from XML DTD validation to view-update triggers. I offered midterm and final exams—multiple-choice, and crafted carefully so the problems weren’t solvable by running queries or checking Wikipedia. (Creating these exams, at just the right level, turned out to be one of the most challenging tasks of the entire endeavor.) To add a personal touch, and to amplify the strong sense of community that quickly welled up through the Q&A Forum, each week I posted a “screenside chat” video—modeled after Franklin D. Roosevelt’s fireside chats—covering topics ranging from logistical issues, to technical clarifications, to full-on cheerleading for those who were struggling.

Meanwhile back on the campus front, the Stanford students worked through exactly the same materials as the public students (except for the multiple-choice exams), but they did get something more for their money: hand-graded written problems with more depth than the automated exercises, a significant programming project, traditional written exams, and classroom activities ranging from interactive problem-solving to presentations by data architects at Facebook and Twitter. There’s no question that the Stanford students were satisfied: I’ve taught the course enough times to know that the uptick in my teaching ratings was statistically significant.

One interesting and surprisingly large effect of having 60,000 students is the need for absolute perfection: not one tiny flaw or ambiguity goes unnoticed. And when there’s a downright mistake, especially in, say, an exam question … well, I shudder to remember. The task of correcting small (and larger) errors and ambiguities in videos, quizzes, exercises, and other materials, was a continuing chore, but certainly instructive.

What kept me most engaged throughout the course was the attitude of the public students, conveyed primarily through emails and posts on the Q&A Forum. They were unabashedly, genuinely, deeply appreciative. Many said the course was a gift they could scarcely believe had come their way. As the course came to a close, several students admitted to shedding tears. One posted a heartfelt poem. A particularly noteworthy student named Amy became an absolute folk hero: Over the duration of the course Amy answered almost 900 posted questions. Regardless of whether the questions were silly or naive, complex or deep, her answers were patient, correct, of just the right length, included examples as appropriate, and were crafted in perfect English. Amy never revealed anything about herself (although she agreed to visit me after the course was over), despite hundreds of adoring public thank-you’s from her classmates, and one marriage proposal!

So who were these thousands and thousands of students? I ran a survey that revealed some interesting statistics. For example, although ages and occupations spanned the gamut, the largest contingent of students were software professionals wanting to sharpen their job skills. Many students commented that they’d been programming with databases for years without really knowing what they were doing. Males outnumbered females four to one, which is actually a little better than the ratio among U.S. college computer science majors. Students hailed from 130 countries; the U.S. had the highest number by a wide margin, followed by India and Russia. (China unfortunately blocked some of the content, although a few enterprising students helped each other out with workarounds.) On you can find the full survey results via the FAQ page, as well as some participation and performance statistics.

Were there any negatives to the experience? Naturally there were a few complainers. For example, in my screenside chats I often referred to the “eager beavers” who were working well ahead of the schedule, and the “procrastinators” who were barely meeting deadlines. Most students enjoyed self-identifying into the categories (some eager-beavers even planned to make T-shirts), but a few procrastinators objected to the term, pointing out that they were squeezing the course between a full-time job or two and significant family obligations. A number of students were disappointed by the low-tech, non-Stanford-endorsed “statement of accomplishment” they received at the end; despite ample warnings from the start, apparently some students were still expecting official certification. I can’t help but wonder if some of those students were the same ones who cheated; I did appear to have quite a number of secondary accounts created expressly for achieving a perfect score. I made it clear from the start that I was assuming students were in it to learn, and cheating was not something I planned to prevent or even think about. Of course in the long run of online education, the interrelated topics of certification and cheating will need to be addressed.

So what happens next? Stanford is launching quite a few more courses in the same style, and I’ll offer mine again next fall. MIT has jumped on the bandwagon; other universities can’t be far behind. Independent enterprises such as the pioneering Khan Academy, and the recently-announced Udacity, are sure to play into the scene. There’s no doubt we’re at a major inflection point in higher education, both on campus and through internet distribution to the world. I’m thrilled to have been an early part of it.

Meanwhile here are a few more numbers: A few months after the initial launch we now have over 100,000 accounts, and we’ve accumulated millions of video views. Even with the course in a self-serve dormant state, each day there are a couple of thousand video views and around 100 assignments submitted for automated grading. All to learn about databases! Wow. Check it out at

Blogger’s Profile:

Jennifer Widom is the Fletcher Jones Professor and (currently) Chair of the Computer Science Department at Stanford University. She was a Research Staff Member at the IBM Almaden Research Center before joining the Stanford faculty in 1993. Her research interests span many aspects of nontraditional data management. She is an ACM Fellow and a member of the National Academy of Engineering and the American Academy of Arts & Sciences; she received the ACM SIGMOD Edgar F. Codd Innovations Award in 2007.

Copyright @ 2012, Jennifer Widom, All rights reserved.



  • Lalitha Murthy on February 25, 2012

    I am a Business English trainer in India. After reading your article ,I am wondering how this can be incorporated in courses here.
    Awesome work!!

  • C on February 26, 2012

    Don’t be discouraged by any negative comments or cheaters Dr. Widom. The class was excellent – I completed it (without a perfect score 🙂 ) and found it to be the best technical education course I have ever had.

  • Alok on February 26, 2012

    I was one of the people who took the course and could not thank you (and the staff) enough for the wonderful course, yet will do so on every opportunity!

    An interesting thing from the course also was how the gap between eager-beavers and deadline-driven people widened as the course went along. This caused not only undue pressure on some of us during some of the weeks, the forum discussions also bifurcated correspondingly, making it harder for people to find questions relevant to them. I find it a pity that some of the new courses are still not catering to this issue as they have put several weeks of videos online ahead of time!

  • harinee on February 26, 2012

    Proud to say that I was one of the 6500 who achieved a score.So Amy was a real student because there were stories that it was Professor herself posing as Amy 🙂
    Anyway quite delighted to hear that you are back on next fall. Hope its next step from the previous class, I will be all set to attend it!

  • Ariel on February 26, 2012

    Thank you for all your time and effort! The class was great.

  • Henrik Warne on February 27, 2012

    It’s nice to read that it was a rewarding experience for Professor Widom as well. I took the class and thought that it was excellent!

    I wrote about my experience of it here:

  • Wang Jing on February 27, 2012

    Thank you Professor Widom!

  • Kalpana Mohan on February 28, 2012

    Hi Jennifer, I’m wowed! What a lot of work but how satisfying to have been able to teach so many people in one shot. Thanks for sharing this. I’ll tell Mohan and Parthiv to read this post.
    Why don’t you ask the Stanford Magazine to repost this piece on its site? You’ll get a lot more readers that way. Since you’ve done such a nice job of writing it up, I think you should get more mileage out of it.


  • Pervys Rengifo Rengifo on February 28, 2012

    Thank Teacher: In Colombia, many people took this course and the comments I have received have been excellent. I signed on track at the end of last year and I have been very helpful, all materials and activities available in the self-service arrangement. I had the opportunity to take the course in Machine Learning (Andrew Ng) and Introduction to Artificial Intelligence (Norvig and Sebastian Thrun Piter), and the result was a very enriching experience, with teachers who were very generous with knowledge. I learned a lot. I have a blog in Spanish, which I mentioned my experience:
    Thank you very much and I will be attentive to the new edition of her courses Introduction to databases.

  • Tony Sidaway on March 2, 2012

    Well done Dr Widom. I’m glad your Stanford students also appreciated the hard work and great organizing abilities you brought to this new mode of teaching. I’ll be sure to recommend your course in Autumn, as a professional who has worked with databases to DBA and architect level but still learned much from your free online course.

  • Dan Scott on March 2, 2012

    Jennifer, Thank you. I took the other two classes since I first built my own database (hashing algorithms and all) in 1974 and have taught and used databases ever since. My experiences in the other classes fall into the “almost in tears in gratitude” side of the spectrum. After 44 years as an IT professional it is wonderful to be so excited about my profession again.

    As for the teaching modality — no question. The rest of the world will absolutely have to adapt or it will be trampled in the stampede as people worldwide experience the power and sheer joy of learning in the “flipped classroom.” And I agree that the Stanfords and MITs of the world have nothing to fear as long as professors like you leverage the ability to go beyond the simple mastery of material.

  • Marina Chernyavskaya on March 4, 2012

    Thank you again, Prof.Widom, for this excellent course! I’m so proud to have been among those first 100 000 students on 2011 online course.

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