0:00:01.135,0:00:03.111 Everyone is both a learner 0:00:03.111,0:00:04.623 and a teacher. 0:00:04.623,0:00:07.079 This is me being inspired 0:00:07.079,0:00:08.270 by my first tutor, 0:00:08.270,0:00:09.215 my mom, 0:00:09.215,0:00:11.838 and this is me teaching 0:00:11.838,0:00:13.791 Introduction to Artificial Intelligence 0:00:13.791,0:00:15.031 to 200 students 0:00:15.031,0:00:16.303 at Stanford University. 0:00:16.303,0:00:17.759 Now the students and I 0:00:17.759,0:00:18.935 enjoyed the class, 0:00:18.935,0:00:20.351 but it occurred to me 0:00:20.351,0:00:22.062 that while the subject matter 0:00:22.062,0:00:23.351 of the class is advanced 0:00:23.351,0:00:24.039 and modern, 0:00:24.039,0:00:26.358 the teaching technology isn't. 0:00:26.358,0:00:28.694 In fact, I use basically 0:00:28.694,0:00:31.064 the same technology as 0:00:31.064,0:00:33.694 this 14th-century classroom. 0:00:33.694,0:00:36.494 Note the textbook, 0:00:36.494,0:00:39.438 the sage on the stage, 0:00:39.438,0:00:41.337 and the sleeping guy 0:00:41.337,0:00:42.238 in the back. (Laughter) 0:00:42.238,0:00:45.175 Just like today. 0:00:45.175,0:00:48.286 So my co-teacher, 0:00:48.286,0:00:49.926 Sebastian Thrun, and I thought, 0:00:49.926,0:00:51.700 there must be a better way. 0:00:51.700,0:00:53.354 We challenged ourselves 0:00:53.354,0:00:54.645 to create an online class 0:00:54.645,0:00:56.276 that would be equal or better 0:00:56.276,0:00:58.612 in quality to our Stanford class, 0:00:58.612,0:01:00.822 but to bring it to anyone 0:01:00.822,0:01:02.452 in the world for free. 0:01:02.452,0:01:05.020 We announced the class on July 29th, 0:01:05.020,0:01:08.229 and within two weeks, 50,000 people 0:01:08.229,0:01:09.636 had signed up for it. 0:01:09.636,0:01:12.741 And that grew to 160,000 students 0:01:12.741,0:01:14.805 from 209 countries. 0:01:14.805,0:01:16.613 We were thrilled to have 0:01:16.613,0:01:17.734 that kind of audience, 0:01:17.734,0:01:20.373 and just a bit terrified that we 0:01:20.373,0:01:22.684 hadn't finished preparing the class yet. (Laughter) 0:01:22.684,0:01:24.296 So we got to work. 0:01:24.296,0:01:25.932 We studied what others had done, 0:01:25.932,0:01:28.255 what we could copy and what we could change. 0:01:28.255,0:01:30.916 Benjamin Bloom had showed 0:01:30.916,0:01:32.725 that one-on-one tutoring works best, 0:01:32.725,0:01:34.853 so that's what we tried to emulate, 0:01:34.853,0:01:36.293 like with me and my mom, 0:01:36.293,0:01:37.798 even though we knew 0:01:37.798,0:01:39.716 it would be one-on-thousands. 0:01:39.716,0:01:41.917 Here, an overhead video camera 0:01:41.917,0:01:43.749 is recording me as I'm talking 0:01:43.749,0:01:45.428 and drawing on a piece of paper. 0:01:45.428,0:01:47.837 A student said, "This class felt 0:01:47.837,0:01:48.989 like sitting in a bar 0:01:48.989,0:01:50.468 with a really smart friend 0:01:50.468,0:01:51.672 who's explaining something 0:01:51.672,0:01:53.973 you haven't grasped, but are about to." 0:01:53.973,0:01:56.089 And that's exactly what we were aiming for. 0:01:56.089,0:01:58.877 Now, from Khan Academy, we saw 0:01:58.877,0:02:00.701 that short 10-minute videos 0:02:00.701,0:02:02.477 worked much better than trying 0:02:02.477,0:02:04.548 to record an hour-long lecture 0:02:04.548,0:02:06.965 and put it on the small-format screen. 0:02:06.965,0:02:09.157 We decided to go even shorter 0:02:09.157,0:02:10.805 and more interactive. 0:02:10.805,0:02:13.052 Our typical video is two minutes, 0:02:13.052,0:02:14.804 sometimes shorter, never more 0:02:14.804,0:02:17.493 than six, and then we pause for 0:02:17.493,0:02:18.860 a quiz question, to make it 0:02:18.860,0:02:20.738 feel like one-on-one tutoring. 0:02:20.738,0:02:23.140 Here, I'm explaining how a computer uses 0:02:23.140,0:02:24.388 the grammar of English 0:02:24.388,0:02:26.565 to parse sentences, and here, 0:02:26.565,0:02:28.629 there's a pause and the student 0:02:28.629,0:02:30.866 has to reflect, understand what's going on 0:02:30.866,0:02:32.506 and check the right boxes 0:02:32.506,0:02:33.923 before they can continue. 0:02:33.923,0:02:36.371 Students learn best when 0:02:36.371,0:02:37.619 they're actively practicing. 0:02:37.619,0:02:39.915 We wanted to engage them, to have them grapple 0:02:39.915,0:02:42.883 with ambiguity and guide them to synthesize 0:02:42.883,0:02:44.548 the key ideas themselves. 0:02:44.548,0:02:46.260 We mostly avoid questions 0:02:46.260,0:02:47.971 like, "Here's a formula, now 0:02:47.971,0:02:49.046 tell me the value of Y 0:02:49.046,0:02:50.258 when X is equal to two." 0:02:50.258,0:02:52.075 We preferred open-ended questions. 0:02:52.075,0:02:55.253 One student wrote, "Now I'm seeing 0:02:55.253,0:02:57.115 Bayes networks and examples of 0:02:57.115,0:02:58.683 game theory everywhere I look." 0:02:58.683,0:03:00.421 And I like that kind of response. 0:03:00.421,0:03:02.227 That's just what we were going for. 0:03:02.227,0:03:04.421 We didn't want students to memorize the formulas; 0:03:04.421,0:03:05.611 we wanted to change the way 0:03:05.611,0:03:06.701 they looked at the world. 0:03:06.701,0:03:08.027 And we succeeded. 0:03:08.027,0:03:10.427 Or, I should say, the students succeeded. 0:03:10.427,0:03:12.346 And it's a little bit ironic 0:03:12.346,0:03:15.259 that we set about to disrupt traditional education, 0:03:15.259,0:03:17.275 and in doing so, we ended up 0:03:17.275,0:03:18.859 making our online class 0:03:18.859,0:03:21.186 much more like a traditional college class 0:03:21.186,0:03:23.027 than other online classes. 0:03:23.027,0:03:26.242 Most online classes, the videos are always available. 0:03:26.242,0:03:28.059 You can watch them any time you want. 0:03:28.059,0:03:30.346 But if you can do it any time, 0:03:30.346,0:03:31.851 that means you can do it tomorrow, 0:03:31.851,0:03:33.259 and if you can do it tomorrow, 0:03:33.259,0:03:35.421 well, you may not ever 0:03:35.421,0:03:37.179 get around to it. (Laughter) 0:03:37.179,0:03:39.371 So we brought back the innovation 0:03:39.371,0:03:41.458 of having due dates. (Laughter) 0:03:41.458,0:03:42.770 You could watch the videos 0:03:42.770,0:03:44.682 any time you wanted during the week, 0:03:44.682,0:03:45.837 but at the end of the week, 0:03:45.837,0:03:47.554 you had to get the homework done. 0:03:47.554,0:03:49.467 This motivated the students to keep going, and it also 0:03:49.467,0:03:52.323 meant that everybody was working 0:03:52.323,0:03:53.841 on the same thing at the same time, 0:03:53.841,0:03:55.338 so if you went into a discussion forum, 0:03:55.338,0:03:58.042 you could get an answer from a peer within minutes. 0:03:58.042,0:04:00.981 Now, I'll show you some of the forums, most of which 0:04:00.981,0:04:03.747 were self-organized by the students themselves. 0:04:03.747,0:04:06.971 From Daphne Koller and Andrew Ng, we learned 0:04:06.971,0:04:08.967 the concept of "flipping" the classroom. 0:04:08.967,0:04:10.262 Students watched the videos 0:04:10.262,0:04:11.850 on their own, and then they 0:04:11.850,0:04:13.560 come together to discuss them. 0:04:13.560,0:04:16.717 From Eric Mazur, I learned about peer instruction, 0:04:16.717,0:04:19.341 that peers can be the best teachers, 0:04:19.341,0:04:20.773 because they're the ones 0:04:20.773,0:04:23.621 that remember what it's like to not understand. 0:04:23.621,0:04:26.302 Sebastian and I have forgotten some of that. 0:04:26.302,0:04:28.701 Of course, we couldn't have 0:04:28.701,0:04:30.333 a classroom discussion with 0:04:30.333,0:04:31.879 tens of thousands of students, 0:04:31.879,0:04:35.365 so we encouraged and nurtured these online forums. 0:04:35.365,0:04:38.413 And finally, from Teach For America, 0:04:38.413,0:04:39.894 I learned that a class is not 0:04:39.894,0:04:41.390 primarily about information. 0:04:41.390,0:04:44.221 More important is motivation and determination. 0:04:44.221,0:04:46.061 It was crucial that the students see 0:04:46.061,0:04:47.861 that we're working hard for them and 0:04:47.861,0:04:49.270 they're all supporting each other. 0:04:49.270,0:04:52.238 Now, the class ran 10 weeks, 0:04:52.238,0:04:56.149 and in the end, about half of the 160,000 students watched 0:04:56.149,0:04:57.712 at least one video each week, 0:04:57.712,0:05:00.405 and over 20,000 finished all the homework, 0:05:00.405,0:05:02.069 putting in 50 to 100 hours. 0:05:02.069,0:05:03.622 They got this statement of accomplishment. 0:05:03.622,0:05:05.741 So what have we learned? 0:05:05.741,0:05:08.557 Well, we tried some old ideas 0:05:08.557,0:05:10.214 and some new and put them together, 0:05:10.214,0:05:12.296 but there are more ideas to try. 0:05:12.296,0:05:14.110 Sebastian's teaching another class now. 0:05:14.110,0:05:15.478 I'll do one in the fall. 0:05:15.478,0:05:19.238 Stanford Coursera, Udacity, MITx 0:05:19.238,0:05:21.509 and others have more classes coming. 0:05:21.509,0:05:22.997 It's a really exciting time. 0:05:22.997,0:05:24.469 But to me, the most exciting 0:05:24.469,0:05:27.445 part of it is the data that we're gathering. 0:05:27.445,0:05:30.141 We're gathering thousands 0:05:30.141,0:05:31.797 of interactions per student per class, 0:05:31.797,0:05:34.005 billions of interactions altogether, 0:05:34.005,0:05:36.509 and now we can start analyzing that, 0:05:36.509,0:05:37.973 and when we learn from that, 0:05:37.973,0:05:39.214 do experimentations, 0:05:39.214,0:05:41.454 that's when the real revolution will come. 0:05:41.454,0:05:44.230 And you'll be able to see the results from 0:05:44.230,0:05:46.493 a new generation of amazing students. 0:05:46.493,0:05:48.746 (Applause)