Identifying Usability Issues in Instant Messaging Apps on iOS and Android Platforms

Table 2

The 5-point Likert scale used within the heuristic evaluation.

Rating	Description
0	I do not agree that this is a usability problem at all
1	Cosmetic problem only. Need not be fixed unless extra time is available on project
2	Minor usability problem. Fixing this should be given low priority
3	Major usability problem. Important to fix, so should be given high priority
4	Usability catastrophe. Imperative to fix this before product can be released