Consistency and Standard

Good example:

In this google hangout interface, the clock icon leads me to a screen that shows recent calls. I find the choice of the icon to be pretty intuitive and consistent with my prior exposure. Especially when I realize that my iPhone also applies the same clock icon to signifies calling log (as show below).

Bad Example: Line App

Line is a communication app that lets you send messages and make online call and update statuses.

Considering the above screen, if want to look at call history (ex. recent calls or misses) which button would you click?

Instinctively, I hit the clock icon. However, it instead brings me to a screen that shows a facebook-style newsfeed feature called timeline (depict below)

Meanwhile, to actually get to the call history, I have to click the phone button to get the following screen:

This is inconsistent with my prior knowledge and violates the design principle. I am accustomed to associate the phone icon with the screens that allows me to enter phone numbers and make a call.  For example,

  leads to  

Therefore, the use of a phone icon as a lead to the call history screen is a mismatch that creates confusion.

Redesign:

A simple way to redesign this is to:

1. let the ‘home’ icon leads to the newsfeed (timeline) screen instead (Instagram also adopts home icon for the same purpose).
2. Use the clock icon to lead to the call history screen.