the data that google shows from websites is provided by websites as structured markup, websites started providing this with the expectation that it would provide better ranking. Nowadays, however, google could probably just render the same thing thorugh nlp without any additional hints from the sourced pages
From a CSS perspective, shadows, opacity, round borders, and other transformations are very expensive, so flat design is also a matter of resources constraint, they might look fluid, because with time the rendering backend got GPU speed ups, but they would still consume more power/ run a device hotter; this is probably less relevant on native guis..
it would be more like different courses are best at teaching the same thing in a particular way that works best with a subset of people, so the top would be made of the set of courses that works with the majority of the population. The problem is that the way humans learn is not exactly understood, is it even a finite set? And what is its diatribution? Can it change through time/culture? Can it be identified in genetic traits? So if the learning methodology changes through time the best courses would also follow with it
indeed thats probably also one of the most important reasons why they went on funding their own shows, and I don't think that there is another company that tries to bootstrap regional quality shows like netflix. As setting up your own streaming platform becomes easier most of the advantage netflix would provide is maybe just easier service offering outside of the main region of the network and less legal burden
My experience with russian or swedish is that the comments give a lot more insight on many excercises and what it is they are trying to teach and the grammar part of things. If you just chug along without taking the time to browse around then very little remains with you. I am not sure this is a compliment to Duolingo though as I am mostly praising the usefulness if their users...
