Basically what I want to learn is how popular or useful is the swipe in comparison to the tap button in Tinder? Which one do users prefer? Are there any numbers or data about this topic?
I read some stuff but they did not answer my question:
http://www.quora.com/Which-mobile-interface-has-a-better-UX-Tinder-swipe-left-right-or-Hot-or-Not-tap-buttons
http://www.quora.com/Are-Tinder-Jelly-and-other-finger-swipe-interfaces-the-future-of-mobile-application-design
I have developed a few products that came to such discussions and the consensus ( not an official metrics study ) was always a swipe. The very gesture of a swipe mimics your like/dislike of whatever you are selecting/choosing. Instinctively it is more satisfying to swipe. However depending on what product you are building a tap might just do the job. I think also if you do not address such subtle way of navigation at launch of the app then the user might get confused. But by now I think it has become a rather known way of navigation.
You should look at this study :
Tap, Swipe, or Move: Attentional Demands for Distracted Smartphone Input
The conclusion is probably the most relevant part.
"In this paper, we analyze the relative cognitive cost of motion gestures, tap and surface gestures as input for smartphone devices under conditions of light distraction. We show that, for both walking and eyes-free input, the cognitive cost of motion gestures (measured as a function of reaction time) is statistically indistinguishable from the cognitive costs of taps and gestures. As a result, motion gestures represent a viable input alternative for situations where eyes-free input may be required. "
