A modern automobile is less similar to a horse carriage than an early automobile. On the other hand, it's more similar to a horse carriage than, say, a washing machine. Compared to a horse carriage, a modern automobile is faster, lower to the ground, typically enclosed, and more aerodynamic. On the other hand, it still has 4 wheels and a set of seats.
Similarly, I think the current iteration of 'online classes' is more similar to what online education will look like in 10, 20, or 50 years.
You assert that a lecture is the worst way to teach. What is a book or essay, but a lecture in written form? For some students, or some subjects, written text with diagrams might be superior. For others, a live voice, with gestures and diagrams might be superior. It's worth pointing out that, when a lecture is recorded, it can be sped up, slowed down, rewound, and so on. If a transcript is available, it can be skimmed for recall.
But, you might argue, lectures, essays, and any such static methods are still 'the worst'. Give me Socratic dialogues, interactive diagrams, hands-on labs and experiments! A - I'd assert that for some subjects (or portions of subjects), a lecture is actually better. B - This can and has been done in online classes, just as in real classes. In some ways, even attempting to use these 'new and modern' methods could be seen as an anachronism, to the extent they look similar to existing methods used in live classrooms.
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As for certification, it's worth noting that some online course sites are positioning themselves as learning + certification sites. Also, isn't the blanket idea of 'certification' something of an anachronism? ;). Many on HN would argue that when hiring, a cert or degree is only a very rough filter, and interviews / work samples are superior for assessing competency in a subject.
Think about the current state of offline certification - we have things like University Degrees, CISSP, and the Bar.
University Degrees are a broad indicator of a person not being stupid, and perhaps having studied some particular topic at one point in their lives. On the other hand, most jobs treat them as necessary but not sufficient, and other jobs treat them as optional. Once a candidate is in front of an interviewer, a Degree probably won't sway the hiring decision much.
Then there's more specific certifications, like the CISSP. Like you were suggesting, the CISSP can be obtained without necessarily taking any other classes, as long as one has acquired the necessary knowledge and experience. Those hiring treat this certification anywhere from absolutely necessary, to nice but optional, to an indication that a candidate is undesirable.
And then there's certifications like the Bar. While not technically requiring taking any class, it would be fairly difficult to pass without one. It's an absolute necessity to have, to work in that field.
University Degrees range from mildly to very expensive (but at least some multiple thousands of dollars), and are a weak indicator. The CISSP exam is ~$500, not counting study materials, and is an 'ok' indicator. Merely taking the Bar will run multiple thousands of dollars, not counting the necessary classes, and is a strong indicator.
Where do you see your envisioned online certification service? Do you think you can crack the problem of actually useful certification, without charging students multiple hundreds of dollars per cert?