Rhodora! if the sages ask thee why
This charm is wasted on the earth and sky,
Tell them, dear, that, if eyes were made for seeing,
Then beauty is its own excuse for Being;
— Ralph Waldo Emerson
The usability of a tool is influenced by a variety of factors. As humans, one of the ways we choose a tool is based on its suitability to our biology. For example, we may perceive a tool and ask “how efficient can I be with this tool based on its ergonomics?” It’s only natural to ask this question because we’re human and we complete tasks with our bodies (aided by the tool). Another factor which influences usability based on our biology is aesthetic beauty. Humans complete tasks and humans have eyes. So, as Emerson observed, there is utility in beauty for it’s own sake. But you don’t just have to take my word for it.
There is a phenomenon in the world in which people perceive aesthetically-pleasing designs as easier to use than less-aesthetically-pleasing designs. This effect has been observed and documented by Masaaki Kurosu and Kaori Kashimura in their work “Apparently Usability vs. Inherent Usability”. Kurosu and Kashimura found that interface designers are constantly making efforts to make their products more efficient, easier to understand, and more intuitive. But whether or not these goals are achieved is difficult to ascertain without people actually using those products. No matter how inherently usable a product is designed to be, it is meaningless if people don’t find the product apparently usable enough to buy it. In other words, products should be apparently usable as well as inherently usable.
Kurosu and Kashimura found that what makes a product “easy-to-use” in the mind of users has less to do with the inherent usability incorporated by engineers and designers and more to do with it’s apparent usability, in other words, its outward good looks:
apparent usability is less correlated with the inherent usability compared to the apparent beauty. This suggests that the user may be strongly affected by the aesthetic aspect of the interface even when they try to evaluate the interface in its functional aspects.
The conclusion here seems to be that aesthetic designs which look easier to use have a higher probability of actually being used, irregardless of whether or not they are actually so. This being the case, designers should strive not only to improve inherent usability but also brush up on the product’s apparent usability through beauty and aesthetics.
To summarize: a usable product that’s ugly will have its painstaking-designed “inherent usability” rendered moot because of its poor aesthetics. This is (at least in part) the value and promise of visual design as a discipline.