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 and motivations. In this moment of the research, I decide for three main methods: usability tests, design probes (diary of study) and interviews.
I just wondering if someone know about similar case, research or have some tips about other methods/techniques for the pre-tests with users.
I really appreciate any help you can provide!