NEAL CONAN, HOST:
Stanford computer science professor Andrew Ng put his machine learning class online last year, and to his surprise, more than 100,000 students showed up. To reach that many students in traditional settings, he said, I would have to teach my normal Stanford class for 250 years. This is different from online universities and the lectures that many colleges have put online for free for years. This class was interactive, with quizzes, questions and answers, a grade and a certificate of completion. Now, Andrew Ng's new company, Coursera, which he founded with his colleague Daphne Koller, offers anyone unprecedented access to classes from top universities in more than three dozen subjects, all for free.
If you've taken classes online, what works, and what are the problems? Give us a call: 800-989-8255. Email us: talk@npr.org. And you can also join the conversation at our website. That's at npr.org, click on TALK OF THE NATION. Andrew Ng joins us now by smartphone from Mountain View in California. Nice to have you with us today.
ANDREW NG: Hi. Thanks for having me.
CONAN: How soon after you posted this class online did you realize that you were on to something big?
NG: You know, it was - I think within two days of posting something online, there were thousands of students signed on, which were a lot more students than I had ever taught before in my life. And in the following months, we built up to 100,000. That was a big surprise to all of us, that there were this many students wanting to learn about machine learning.
CONAN: Machine learning. This is obviously a very advanced science course. Are there that many - I guess there are that many people pretty interested in it.
NG: Yeah. Machine learning is a technology that's used widely throughout Silicon Valley. It powers all of our computers today. But it is a somewhat advanced, esoteric topic. I think this is a sign of how much hunger there is out in the world for high quality courses from universities like Stanford. And I think we're seeing the world change with, you know, top universities like Stanford, Princeton, Michigan, Penn putting free online courses for anyone to take.
CONAN: How did Stanford react to offering this course for free, when they charge paying students quite a bit for it?
NG: You know, when you talk to top universities, ultimately, I think the mission of top universities is to educate people and, frankly, not to make money. And I think when you talk to a professor of a top university and offer them the technology to teach tens or hundreds of thousands of students, the answer is almost always an enthusiastic yes. Most professors are passionate about what they do and found that - and took on these jobs to advance the state of the arts and really not to make money.
CONAN: Similarly, I guess, parents might have a question about why are you offering these courses for free when their kids are paying, what, $40,000 a year to go to Stanford.
NG: Oh, that's a great question. So what is the real value of attending a top university? I think it's not just the content, because the content is increasingly for free on the Web anyway. Instead, I think the value of attending a top university like Princeton, Stanford and so on is really the interactions between the students and the faculty and in the interactions of other students. And in fact, by putting the content on the Web, what we're seeing is many of the universities using what's called the flipped classroom, in which you ask the students to watch the videos at home and then come in to the classroom to talk to the professor. So by putting content on the Web, we're actually, I think, making, you know, helping make university education much more interactive and - between the professor and the students. And so hopefully improving the quality of education at these top universities as well.
CONAN: And one of the things that interested me about this - the way this works is that everybody can ask questions, and then there's sort of this group discussion, a little like Yelp, as to which questions rise to the top.
NG: Yeah. So in a class of 100,000 students, you know, what happens when you have 100,000 students - 100,000 voices all talking the same time? Just yesterday, the Intro to Sociology class from - just launched on the Coursera platform, and already, sort of, what - less than 48 hours later, there are already tens of thousands of students participating in the discussion. And part of the technology design for the website was to allow tens of thousands of students to speak simultaneously, but for answers and questions to be brought up and down, so that the most helpful and interesting comments get - kind of bubble up to the top. So in fact, the sociology class just started yesterday and, you know, yesterday and today I was seeing just a tremendous volume of exciting discussions with students who come from all over the world.
CONAN: And then there's the question of quizzes and tests and that sort of thing. How do you grade all those?
NG: You know, initially we started off with auto grading, and it turns out that, you know, when we think about grading, we often think about assessing or evaluating students. But it turns out that as educators, we know that the far more important purpose of quizzes and homeworks is not to test the student but to give students the opportunity to practice with the material and thus remember the material longer.
So in the past few months, we've developed very complex auto grading things, where you not just - not just multiple choice, but things like math derivation checking and also peer assessments, where students grade each other's work and give each other feedback. So recently, we had a human-computer interfaces class, an HCI class, a kind of design class, where students are submitting design homeworks and really grading each others' work. That seems to be going very well too.
CONAN: That's interesting because that opens the way toward discussions of how you can possibly - one thing to teach mathematics courses or machine-learning courses, another to go to poetry or creative writing.
NG: Yeah. In fact, when we were visiting - when my co-founder Daphne and I were visiting UPenn and spoke with the poetry instructor there and told him, you know, well, would you like to teach a poetry class and put all your assessments in the form of multiple choice? He basically said, you know, get out of my office. And it was talking to partner universities that we realized that peer grading is really necessary in order to help students engage in some of the more critical thinking and open-ended exercises.
One of my favorites also - I think next week, there's a class on health policy that's about to launch. And this is something that's on my mind a lot again since the Supreme Court decision is coming down. And I think that's another example of a class where, you know, thinking through health policy, right, such an important issue. Is it really possible to do everything using multiple choice? But I think these sorts of peer assessment capabilities are key to these - especially the less technical, the humanities, discussion-based classes.
CONAN: You talked about the value of attending a place physically like Stanford or Princeton. One of the things you do if you complete your work successfully is get a degree. What do the online students get?
NG: In most of the courses that have been offered so far, the instructors or universities having giving - have been giving out a certificate or what we called the statement of accomplishment. It's up to the individual instructor, up to the individual university whether or not these statements will be offered for a particular class. But for the classes that have been offering these, we've been seeing many students already take these, you know, certificates and proudly list them in their resume and also use them successfully to get new jobs and get raises. I think it is important when a student completes a class that, you know, whenever possible, we try to provide them an opportunity to document their accomplishment in the class in a way that helps them get better jobs.
CONAN: We're speaking with Professor Andrew Ng, computer science professor at Stanford University. And now he is the founder, with his colleague Daphne Koller, of Coursera, which offers a broad range of interactive online courses. Let's see if we'd get some callers on the line. If you've taken online courses, what works, and what are the problems? 800-989-8255. Email: talk@npr.org. And let's start with Kayla, and Kayla with us from Cheyenne, Wyoming.
KAYLA: Hi. I'm enrolled in the community college here in Cheyenne, and a lot of the classes I've had to take are online because I'm a new mom. And one of the problems I've encountered is that teachers seem to be having difficulty engaging the students in meaningful discussion, 'cause the majority of the classes that I have taken have consisted of learning material long enough to take the test and move on to the next subject, and then they tell me that I've completed it. But they don't really have any sort of evaluation discussion where we critically evaluate the material that we've learned. And that's really frustrating for me because I want to know more than just what the book says.
CONAN: And so you - because you're a young parent, you have to time shift to - so you can watch these lectures at a different time?
KAYLA: Actually, a lot of my classes don't even have lectures. They just consist of buying books from the school and then taking the class entirely online. And so the discussions are actually just a forum on the class webpage. I've never once actually watched any type of video for a discussion for any of my classes.
CONAN: And is this - are you getting your money's worth?
KAYLA: I would say yes and no. Yes, because I'm getting what is considered a formal education and providing myself with an opportunity to take care of my child better. But the classes leave a lot to be desired in really understanding and being able to think critically about the material.
CONAN: Well, thank - yeah, I could understand that's a problem. And, Andrew Ng, I assume that's something you considered as you designed your course in the first place.
NG: Yeah. Yes. In fact, you know, one of our motivations for online courses was exactly for, you know, people like Cheyenne who may need to time shift their work and work at odd hours rather than show up regularly. And regarding the interactivity, the Coursera platform has courses in which professors are teaching not just 20 students but, you know, tens of thousands of students. And so we've put a lot of effort into designing, you know, things like ways to hold online office hours, where professors can chat live with a small number of students but broadcasted to a much larger community.
Also, you mentioned a community forum. And we're putting in place mechanisms for students to try to raise the important issues to a professor so a professor can pay personal attention to it. And some professors will record a weekly video in response to student questions. Now, it is challenging for our courses when you have, you know, 10,000 rather than 20 students to have a one-on-one relationship with students. But we're working hard on the technology to do that, and, I think, many students, I hope, you know, end up getting to know their professor somewhat, even though it's one professor teaching 10,000 students at the same time.
CONAN: Kayla, thanks very much for the call. Good luck.
KAYLA: Thank you.
CONAN: We're talking about taking classes online in a very new form. You're listening to TALK OF THE NATION from NPR News. And here's an email question from Barbara in Davis, California: I'm currently taking the Coursera course called Human-Computer Interaction. A most interesting aspect is the peer grading. They have excellent training for grading, speaking as a former university instructor. This week, I've graded responses from students in the Middle East, Colombia, and the Ukraine. I find it fascinating. And one of the things you mentioned, tens of thousands, even hundreds of thousands of students in some courses, they're from all over the world.
NG: Yes, so I think the HCI class had a, I believe, 26,000 homeworks submitted from over the world. And one of the - it turns out that not only is it useful, you know, for students to get feedback from, say, four or five other students. It turns out that in peer grading, the act of a student grading someone else's work is actually pedagogically useful as well. It's been well-documented by grading other people's work or by grading your own work, you actually learn more about the subject, get to see what others' work in the course is like as well. And I think the HCI class represents the first, and then probably the - probably by far the largest experiment in peer grading that has ever been run before.
CONAN: Let's go next to - this is Tim. Tim with us from Cincinnati.
TIM: Hi. How are you?
CONAN: Good. Thanks.
TIM: I just wanted to comment. I'm a non-traditional student. I'm 28. I've returned to college after several deployments with the Army Reserve. I'm currently preparing to leave for Afghanistan within the next month, and online classes have offered me the ability to, you know, still be engaged in school and work towards my degree as I'm balancing my military obligations at the same time.
CONAN: So you're going to continue taking online classes from Kandahar or wherever it is you're going?
TIM: Yeah, correct. I'm currently enrolled in one class - a summer online class, and the goal is to, you know, once I get overseas, is still try to enroll in the classes that meet my availability, my schedule.
CONAN: And what are you studying?
TIM: I'm currently majoring in criminal justice.
CONAN: Well, good luck to you and be safe, OK?
TIM: All right. Thank you very much.
CONAN: Appreciate the phone call. Do you have a...
NG: So, Tim, thank you for your service to our country. I know that last year when Stanford first offered the three online courses for free, I know that there was at least one war fighter, one American war fighter in Afghanistan who was routinely, you know, (unintelligible) the war zone in order to get this homework done in time. And I think of stories like that that inspire me and, you know, I think of the free online courses that we're offering as well can offer a better education to our servicemen fighting a war. So I feel that like that's one of the best things we can be doing.
CONAN: Let's go to Nate, and Nate's on the line from Sacramento.
NATE: Hi. I have actually - as an instructor in higher education, and I had experience online, and one of the big issues that I've experienced is issue with academic integrity, and I'm just wondering, you know, other than my conscience, so this not something I would ever do. But what would prevent me from, say, you know, completing an online course and then saying, OK, I will take that for anybody for a fee, pretend to be you and give you the certificate of completion so that you have a better chance in your next job interview, even though the person I'm completing it for actually has not learned anything or taken the course? How do you address issues of academic integrity and identity online, and particularly with such a large scale?
CONAN: Professor Ng?
NG: Yeah, so I think the academic integrity and cheating is something we spent a long time thinking about. And it's true that, right now, we have relatively weak safeguards against cheating. We - but we are working on a number of technologies to guard against cheating and to verify the identity of the person. And hopefully, we'll be announcing some of those technologies in the coming months. You know, I think it's impossible - I don't think it's possible to completely eliminate cheating. Even, I think, even a few months ago, the SAT exams - the kind of gold standard, right - there was cheating, and one student had managed to impersonate other students for the SAT exam. So I don't think it's impossible to eliminate cheating completely. But with some of the technologies we're working hard on, I think we'll be able to, at least, deter casual cheating and, you know, make it quite a bit harder to pretend to be someone else.
CONAN: Nate, thanks very much.
NATE: You bet.
CONAN: And finally, free, is that going to be sustainable?
NG: So when my co-founder Daphne and I started this company, it was very important for both of us to make the courses free. A lot of people have asked us, you know, why not charge a dollar? Well, it turns out that a lot of people, the most needy people, especially those outside the U.S. may not even have a dollar or may not even have a credit card. I think there'll be plenty of ways to keep the business sustainable and the current ethos - that the current ethos in Silicon Valley is that if you build a website that's engaging and if you are really changing millions of people's lives, there'll be plenty of ways to keep it sustainable. So we have a bunch of ideas, one is maybe to help students interested find jobs. But these are things we'll continue to look at over time.
CONAN: Professor Ng, thank you very much and good luck.
NG: Thank you. It's an exciting adventure.
CONAN: Andrew Ng, computer science professor at Stanford University and, along with Daphne Koller, co-founder of Coursera, which will distribute a broad range of interactive online courses. It's the TALK OF THE NATION from NPR News. I'm Neal Conan in Washington. Transcript provided by NPR, Copyright NPR.