Tracking word strength across language courses.
If I study "mot" in English to French. Then later on study "mot" in Spanish to French, does Duolingo track each separately? Or do I now have a "mot" that has the strength of being studied twice?
And what about the strength of words in the "base" language? My guess is that Duolingo does not track the strength of my English, because I created my user identity as a native English speaker.
But when I study in the Spanish to French course, I get French points, merci beaucoup. But as far as I can see I get no Spanish points and no Spanish word strength improvement because in that case the base language is Spanish.
I can live with that, but it is worth observing (1) my Spanish is much, much weaker than my French. (2) I actually am practicing both languages when I do the Spanish to French course. (3) I am practicing thinking in a foreign language, too, a skill of native polyglots that cannot be improved as easily for me when studying English to X.
(4) That's a lot of data for Duolingo to leave on the table.
I am not so worried about the points. When French to Spanish rolls out :) I'll do that course, too, which should even things out.
But I know my Spanish word strength is improving or holes are being exposed while I study the Spanish to French course, so I think it would improve how Duolingo monitors my Spanish word strength if it tracked the base language, too.
Moreover, I can think of another good reason to track base language word strength: improving the gauge of a person's translation skills. There are some sentences I have seen in Immersion that were poorly translated into English because the reading level of the passage was not preserved in the English. So a complex sentence structure was simplified or words added where they were not needed in English either, if the reading level had been maintained.
You can judge the writing and reading skills of native speakers in their own languages, and I think coming up with a way to do so through existing courses would be a win-win scenario.
Finally, you could also gauge native speakers using the existing certificate tests. So give me the English test. If I don't rock it like a native, you should be more wary of my translations (or go fix your test :) ).