I am making a research about interfaces and usability of mobile apps for learning idioms (duolingo, babel, vox, etc). The research has a objective to gather aspects, such as: efficiency, learnability ...
Background We need to build a system that helps users understand the interconnection among related variables. A concrete example (not ours - but analogous) is the relationship among Temperature, ...
I am looking for a Comparative Report / Benchmarking about apps of learning foreign languages, like Duolingo, Busuu, Babbel etc. Could someone know or provide something similar? Could be a ...