A program should follow the ‘Law of Least Astonishment’. What is this law? It is simply that the program should always respond to the user in the way that astonishes him least.
The Tao of Programming
This is the opening quote in (my OPW mentor) Jim Hall’s capstone titled Usability Themes in Open Source Software. I think it perfectly encapsulates the concept of usability – how easy it is to learn and use something.
Usability plays a major role in the adoption and sustained use of any system, be it physical or virtual. With respect to a new system, it is vital that it be iteratively redesigned incorporating users’ feedback, since there are issues which may be non-obvious to developers who are at best, a subset of the user base (faced this up close in Project Mudra).
Usability is multi-dimensional, a cumulative result of many factors like:
1. Intuitive design: a nearly effortless understanding of the architecture and navigation of the system
2. Ease of learning: how fast a user who has never seen the user interface before can accomplish basic tasks
3. Efficiency of use: How fast an experienced user can accomplish tasks
4. Memorability: after using a system, if a user can remember enough to use it effectively in future visits
5. Error frequency and severity: how often users make errors while using the system, how serious the errors are, and how users recover from the errors
6. Subjective satisfaction: If the user likes using the system
From what I have understood, usability is a measure of how well a system allows you to do your job without getting in the way. Better usability translates to better engagement, better efficiency, better effectiveness and (if that’s the end goal) better revenues too!
Some researchers in this area make a distinction between “big U” Usability and “little u” usability – “big U” Usability is everything that goes into creating a product that works for people (Redish). “Big U” Usability encompasses tools and techniques that can be used before development, during development and after development to support your understanding of the user experience (Barnum). It includes, but is not limited to, “little u” usability (i.e. usability testing). Usability testing is what I will be focusing on during my internship.