I got to see Luis von Ahn the inventor of CAPTCHA discuss his latest crowd sourced venture, Duolingo, which I'm sure everyone has an opinion about, back in 2013 or 2014 at The LAB Miami in Wynwood.

At that point they had ~24 employees. He said his interest was crowdsourcing and thought most of the engineering effort would go toward the crowdsourced translation, but at that time, it was being handled by just two employees.

They brought on two prominent consultant researchers, leaders in the field of language learning and linguistics. The first question they asked the consultants was which part of speech should they present to the learner first. The consultants didn't have an answer. They decided to dedicate engineers to collecting data in order to answer that question.

A big problem with edTech is that we don't know.

▲

rseech01 6 hours ago | parent | next [-]

Very cool to hear that you were at the LAB Miami in 2014, Around 2016, I was trying to organize a group of folks to build a variable spaced repitition application that tied to a off the shelf eeg, to figure out the optimal time to learn at one of the local hackathons.. We had a whole team of folks, some of the Flomio hardware people, and other local startup folks. Never was able to build the prototype at a hackathon, but always thought there is a physiological element to learning, and ed tech in general.

	▲	dataviz1000 6 hours ago \| parent [-]
		> off the shelf eeg We know that mild stress can narrow focus and help learning. "Neural connections do form when you struggle." [0] A little stress is not only good but necessary for learning while a lot of stress causes a breakdown. The trick is being able to judge the stress level of the student and every person is different. The idea of using some type of bio metric data from EEG or blood pressure sensors will help determine a little struggle from a lot of struggle in formative assessment. [0] https://www.youtube.com/watch?v=wh0OS4MrN3E

▲

ks2048 5 hours ago | parent | prev | next [-]

My understanding (in hindsight) is that success of Duolingo had nothing to do with “crowdsourcing” - is that correct? (Beyond maybe stories for fundraising).

It doesn’t seem to have a lot to say about “ed tech” - popularity of apps seems disconnected to popularity

▲

diskzero 6 hours ago | parent | prev [-]

I don’t understand what you mean by “we don’t know”? Are you saying tech entrepreneurs don’t know education? I agree with that. Or are you saying we don’t know what problem to solve?

▲

raddan 6 hours ago | parent [-]

My interpretation of “we don’t know” is that the space of possible instruction methods is huge, and we don’t know what works best. It is easy to think of it as a kind of optimization problem, but that line of thinking quickly runs into a bunch of practical obstacles: different people learn differently, studies with good experimental design take time and resources so it is slow to iterate, and good teaching seems to require deep insights into student motivations and incentives, aspects of teaching that are hard to quantify. We also don’t have great ways to measure outcomes; grades are weakly predictive of future success.

The best teachers seem to combine deep thinking about how to teach with intuition and charisma. The ingredients are hard to replicate.

I do think that this is a nut that we will eventually crack, but it is proving to be a very tough nut.

	▲	duttish 3 hours ago \| parent [-]
		It's also quite possible that the method that works best for one person is completely horrible for another person, but that's just me guessing