An interaction error occurs when a product fails to interact appropriately with a user. One key goal of designing is to eliminate interaction errors.
An interaction error (IE) is what happens when a product:
In both cases, we take the position that the fault lies with the product, and not with the users or external systems.
We distinguish between product failures and interaction errors. A product failure occurs when a product's function or behaviour fails; an interaction error occurs at the interface between product and human, when there is a mismatch between the product's side and the user's side of the interface.
Product failures and interaction errors are often coupled: an IE can lead to a product failure, and a product failure can result in IEs. It's important to distinguish between the two because the two kinds of problems are addressed in very different ways. Product failures are addressed through more careful engineering; interaction errors are addressed through more careful design.
In this course, an IE is specified with two pieces of information:
The mismatch is particularly important and must be described in some detail.
IEs are described with respect to a specific Persona and SUC.
A particular team member has developed a concept as shown to the right. The team member's Persona is Zoya, and their SUC is Making smoothies for the kids. Zoya is known to be elderly, and thus likely the grandparent of “the kids”. One possible interaction error is described below.
STEP: Zoya tries to grip the product when it's sitting on an upper kitchen cabinet.
MISMATCH: The product's shape does not afford Zoya an appropriate grip.
Notice how the details of the mismatch may well drive the need for further research. For instance:
The results of this kind of research must be documented in the situation scan.
A particular team member has developed an “urban vehicle” concept as shown to the right. The team member's Persona is François, and their SUC is Going to work on a rainy day. François is known to be an intern at a corporate law firm in Montreal, and lives in a townhouse about 10km from work. The main entrance of the townhouse has 6 steps down from the front door to the walkway. One possible interaction error is described below.
STEP: François has to carry his vehicle down the porch steps to go to work.
MISMATCH: The product's size, shape, and weight do not afford François an easy and safe way to carry the vehicle down the steps.
Again, notice how the questions drive the need for research. Be sure to include such research in your situation scan.
Also note, the questions themselves are listed above only to stimulate your thinking. In your actual reporting of interaction errors, you would write down the answers to those questions.
TODO Describe consequences and counter-indications.