Today I presented, on behalf of my fellow authors and myself, an exploratory study on expected and experienced usability in electronic consumer products at the IEA2009 congress on ergonomics. You can download the full paper (pdf), or read a summary below. The study shows that expected and experienced usability can differ significantly under the influence of usage, how expected usability can be influenced, and what the effect of poor experienced usability can be.

Aim
In the paper we explore why consumers do not seem to have a very pre-purchase distinct preference for usable products, even though these would probably satisfy them more after purchase. We wanted to explore the hypothesis that this might be due to the fact that it might be to hard for consumers to judge before use whether a product is usable or not. We call the pre-use assumptions that people have about the usability of a product expected usability. Experienced usability is the opinion people have about usability after use. We wanted to explore what product properties influence expected usability, and whether and when there is a difference between expected and experienced usability. And what the consequences of that are.


Method
To study this, we showed people a number of consumer electronics products (1 navigation system, 3 alarm clocks), asked for their opinions through a questionnaire and an in-depth interview, gave them the product to use at home for two weeks, and then reassessed their opinions. So contrary to most studies on this issue people got to use the product for an extended amount of time and in their own environment.

What you see may not be what you get
The results showed that people's assessment of product usability can differ significantly before and after use. Expected usability was influenced by brand, price, styling and functional form. In addition, indications were found that expected usability can be influenced by marketing efforts, previous experiences with similar products, and opinions of other people. It was shown that product appearance (aesthetics and functional form) can be a misleading predictor for experienced usability. In other words: what you see may not be what you get.

Price as an indicator for experienced usability
For one of the alarm clocks a significant gap was found between expected and experienced usability. After having used this product the participants indicated they were considerably less willing to pay the indicated retail price. As one of the participants put it: "I would not use this alarm clock even if I would get it for free!" They seemed to use the price they were willing to pay as an expression for the poor experienced usability. These participants also rated usability as a more important product property before then after use. To paraphrase Tractinsky (2000): "When something is unusable, beauty no longer matters."

Functional form, styling and expected usability
The appearance of the product seemed to impact expected usability in two ways. The functional form aspects, such as number of buttons and screen size seemed to impact the participants' anticipations about the user interface of a product, while the styling of a product seemed to project a more general image of being easy to use or being aimed at a target group for which products need to be easy to use (children). So designers could use a products appearance to heighten expected usability. However, then the experienced usability needs to be in line with expectations, because disconfirmation of expectations is one of the triggers for customer dissatisfaction.

Reference
Kuijk, J.I. van, E.E. Preijde, E.N. Toet, H. Kanis (2009) "Expected versus experienced usability: what you see is not always what you get." IEA2009: 17th World Congress on Ergonomics, August 9-14, Beijing, China.