My PhD thesis focused on voice interface design for people with limited literacy skills. One of the most surprising discoveries for me was that menus and even lists of items aren’t natural concepts that exist outside of a context of literacy. Even for voice interfaces, a touch tone menu (“for X press 1, for Y press 2...”) was a lot harder to navigate than an equivalent voice-based menu (“would you like X, Y, or Z?”). As a side project during my final year of my thesis research, I wrote an iPhone app that unexpectedly propelled me into the world of entrepreneurship, so I ended up pursuing the startup life after I graduated. But this space is still fascinating to me.