The way I think about learning is in three parts. First, you have to know a bunch of things to be successful in life. There is no way to fake it if you dont know multi-digit addition. At some point, if you don't, you will put the wrong things into your calculator and give $20 change on an $18 purchase. (This one happened to me last year). So there is a good body of things you have to know. I think this maps cleanly in k-5 where its pretty inarguable that you need to know how to spell and most everything else they teach you. On the other hand, in secondary grades, it is not as clear. Is it crucial for everyone to know biology? Maybe the amount you can look up on Wikipedia, but a whole year? We can debate what things you need to know (which we do periodically, common core being the latest output), but its clear there are things you have to know.
Second, you have to be able to think. You have to use the things you know to solve problems, sometimes in groups, to create new things, to identify patterns. You can be taught how to think. If you aren't sure of this, talk to people who went to engineering school or law school. The methods great schools teach you about how to think are far more valuable (and more difficult to assess) than what they teach you to know.
Finally, to be a successful person, you have to be able to do things. Getting things done has everything to do with your personal and social abilities. Are you persistent? Are you organized? Can you delay gratification and focus on the long term? Do you work well with others? This third category is much harder to measure than the first two but probably accounts for well over 50% of your success in life, especially modern life. Read Reid Hoffman's - the startup of you - sometime to see the product of a very evolved doers mind. Your career and your life is less shaped by the specific things you know (beyond what you learn k-5) and more by how well you adapt to a rapidly changing world. So knowing less and being able to think and do more is going to serve you well.
In this context, we are getting ready for online learning 2.0. Version 1.0 was the simple translation of teaching and learning online by the pioneers like khan, coursera, udacity and others. Pause and rewind is not what online learning 2.0 will look like. What will it look like? Obviously this is what we are building at my new company, so I'm not going to pre-announce anything specific, but I do think there some obvious things. Online learning will teach you almost everything you need to know. Some of that will be through hundreds of hours of practice. Other will be on-demand (arguably for a lot of what you learn in secondary). But anything that requires personalized attention and infinite patience on the other end of the student will ultimately go online. Physical schools, when they are available to a student, will teach you how to do. Physical places and groups will have big advantages in getting students to change their behavior in the way that these personal and social skills require. In the middle I think we will see online learning systems get better and better at teaching you how to think, but this will likely be the domain of institutional learning for a while.
Of course, it is not quite that simple, but its important to acknowledge the relative strengths of teachers and tech so we can think about how they work together rather than the current debate about how tech will replace teachers. Teachers aren't going anywhere, but their roles will change dramatically over the next two decades. They will be much better paid (because the role will be differentiated the same way professors and TAs are differentiated), they will spend much less time teaching rote skills (the knowing, because that will happen online) and much more time teaching children how to think and how to do. I think we will end up with much happier teachers because of this change, but of course change is hard.
So to me this frame of know, think, and do helps you get clearer on how learning will change over the next 20 years. Now that everyone is online (or coming online faster than you can possibly grow your company), online learning companies have enormous market opportunities. I think we will find that the quality of the learning products they build for the 8 billion people out there makes what we have now in edtech feel like the comparison between the VCR and Netflix.