OneBigWeb

Published on:January 4th, 2006

What defines a great interface design? One typically encounters a wide range of responses to this question. Concepts such as harmony, balance, simplicity, naturalness and powerfullness are offered as qualities that distinguish a great design.

While all these qualities do matter, what we need is a concise set of attributes that can be used to objectively evaluate a interface design. The attributes should be applicable to any type of interface, be it “end user” app interfaces, application programmer interfaces (api’s), progamming languages or even interfaces to a microprocessors.

There are three attributes which when considered collectively, appear to provide us with just that.
1. Genericness : The range of tasks that the interface supports. The tasks would need to be weighted for their value to the user as well for the frequency of usage. A generic app is often thought of as being “powerfull”.
2. Efficiency: The effort required to perform these tasks. It could be measured in terms of mouseclicks or lines of code or what ever best quantifies the effort required.
3. Intuitiveness: The learning required to perform a task. This is a lot more subjective, but could be measured in terms of time and effort required to learn. Qualities like simplicity and harmony contribute to intuitiveness.

Designing interfaces for products typically involves exploring this mutidimensional space defined by these three attributes. Each of these attributes are mutually exclusive. It is relatively easy to focus on one or two of the above, but the real challenge lies in optimizing for all three of them.

Perhaps the one application that is universally acknowledged to have a great design is the spreadsheet. The range and the value of the things it can do is huge. It is very efficient and is magically intuitive. It is not often that we discover as great a paradigm as this.