An Introduction to Usability Harmonics
Usability Harmonics is a much easier to use 'remix' of the somewhat impenetrable Cognitive Dimensions of Notation which is often used for the evaluation of programming language usability.
Usability Harmonics is a framework specifically targeted at evaluating, describing and reflecting on 14 usability characteristics found in software. The framework functions as a design post-mortem, letting you know what's working well, and what isn't; importantly, it also tells you the why, so you can use this knowledge to be a better designer in the future, knowing why a design is good, is as important as knowing why one is bad and this is the framework that will codify that knowledge. As you proceed with the evaluation you can also note defects, though this is optional. Once the evaluation is complete, you can then make a plan on how to improve your designs based on what you know is and isn't working.
In short, you'll have an overview of the processes involved in using your application and how the design supports or hinders these processes; this is in contrast to Heuristic Evaluation where the outcome is generally only a list of software usability defects.
One of the biggest advantages of using Conceptual design when building your software, is that when you build in terms of concepts, you can evaluate in terms of concepts. As a software designer, this will make your job much faster and easier, though of course you can still use this framework if that isn't the case, it will just take a bit longer the first time you do it.
Who can do it​
Usability Harmonics can be used by designers as a discussion tool to reflect on design choices, or by users to articulate their experiences with a system, one of the many strengths of this framework is that it can be used by non UX professionals, all one must do it lean the characteristics and start working through them.
When to do it​
Usability Harmonics is a suitable tool for use at any stage of a product lifecycle as it can be used to not only asses what has already been designed, but it can also form a knowledge base to guide any future design process, in effect, you can perform Usability Harmonics to level up your design team as what works and what doesn’t work should become very apparent due to going through this process. This framework is also complimentary and can be used in combination with any other evaluation technique.
How to do it​
You can begin by familiarising yourself with the key characteristics such as rigidity and invisible links, and then evaluate your design or system against each characteristic, noting areas of concern or where improvements can be made, and importantly, noting where no work needs doing (i.e the design is a success). You can use spreadsheets to track this information.
One critical aspect to be aware of is that acting to change one characteristic can adversely affect another, for example if you want to lower Rigidity (to make things easier to change in your software) you might do this by introducing a new way of working, this in turn may make the Conceptual Gradient worse if the user has to learn more before they can gain the benefit of the new ideas.
The 14 characteristics are not in fact all equal, evaluating the Conceptual Burden is the most important, and in my experience a ‘core review’ of just 6 of them can provide a good base for discussion, of course more complete reviews should be done periodically (or these core reviews should be supplemented by heuristic evaluation). So for the time pressed, the core 6 are:
- Conceptual Burden.
- Invisible Links.
- Premature Commitment.
- Real-time review.
- Rigidity.
- Visibility.