Like any medium, interactive media and interactive systems have design considerations that are specific to the medium. This section reviews some important issues to address as an interaction designer.
Donald Norman literally "wrote the book" on the basics of usability
in interaction design (though he didn't call it interaction design) in
his book: The
Design of Everyday Things
Note that the emphasis of this book is on usability, which implies that the best design satisfies the accomplishment of specific user goals. But I would argue that when you think about interactive systems as more than functional tools, other design factors come into play. If the system is designed to communicate knowledge to the user, then usability becomes only one of several design factors. And if the system is designed for productive interaction where the user creates their own knowledge space, then it becomes a combination funcational tool AND communication, which adds further complications to the design equation.
Interactive systems present an activity for the user that happens over time. In the simplist terms, this is composed of encountering the system, interacting with it, and ending the interaction. How the designer controls this arc of interaction, from beginning to end, creates a distinct character to the system which deeply affects its effectiveness and mode of communication.
issues
- what's the setup - project name, physical introduction, instructions, collateral material?
- is the interaction continuous, or punctuated?
- how does the system output/display change over time (if at all)?
is there a tempo/rhythm to the changes?
- stillness/action
- simplicity/complexity
- order/chaos
- type of information/expression.
- amount of output, intensity
- tone/mood
- is there a beginning, middle and end?
- how does the user get started? how does the interaction end?
examples
- food vending machine
- Hear Music listening station/burner
While many interactive systems are specifically single user, this single user focus limits the power of the system in public and group situations. On the other hand, multiple user systems present a powerful and unique design opportunity where the outcome is the result of a collaboration between users. Or, a multiple user system simply makes for a more efficient use of the system, eliminating the one-person-at-a-time line-up. Plus, even seemingly single user systems such as cell phones turn out to have multiple user aspects.
issues
- does the system allow for single or multi-person simultaneous interactions
- how does the system accommodate a group?
- can others watch/listen or otherwise participate if someone else is interacting? How many?
- how does the transition work when passing interaction from one user to another? Do people line up? Is the object passed from one person to the next?
- can a user choose to share outcomes or not? I.e. what are the privacy and social practices around the interaction and display?
examples
- cell phone
- kiosk
- disneyland ride
- installation art
- online gaming
Interaction design involves not only the design of the relationship between the user and the system, but also the relationships the user has with other users and observers.
issues
- social interaction happens as exchange of skills, tips, commentary, talk, play, strategy
- support and encourage with forums, cheat books, displays visible to others, ancillary materials--brochures, environmental graphics, advertising/promotion, viral marketing
- how can multiple people see/learn what's going on, pass the system around, switch from user to user
examples
- copier
- games
- delicti kid
- airline ticket machine
Interactive systems range in their usability from having a zero learning curve (standard light switch) to very high learning curve (fighter jet cockpit). While some in the interaction field, like Jakob Nielsen, argue that there should always be no learning curve, it really depends on the goals and intent of the system being designed.
issues
- will there be a learning curve?
- can you stage the learning requirements so the user can get something done easily, and then acquire skills?
- how do they learn?
- experimentation
- instructions
- can you make use of social affordances?
- how much previous experience does the design depend on?
- can you rely on standards to help eliminate learning curve, or will you violate standards to create a unique effect?
examples
- video games
- flash websites, e.g. www.undocorp.com
- cell phone
Many interactive systems should be designed with a specific context and scale in mind. For example, if the system is an installation, it can often work better if the design considers the site specificity - lighting, form, purpose of site, etc. In addition, the scale of the work often dramatically impacts the effectiveness - small can draw attention, large can have greater impact, etc.
issues
- how does the project relate to the site?
- ignore it?
- become integral to it or oppose it?
- what are the characteristics of the site?
- lighting, form, features
- history, use
- how will the scale of the project affect it?
examples
- vietnam memorial
- original cell phone vs. current sized phones
- student pavilion
An underexplored area of interaction design is what does the system do when the user is not interacting. The default is for the system to simply wait for the next user action. But there are many alternatives which involve the system interacting with itself--i.e. passive interaction. The system can make decisions on its own, present material, and continue to operate without user interaction every moment.
issues
- does the system come to a stop when waiting for a user action? can it present something while waiting? can the narrative continue?
- does the system time-out after a certain period of inaction?
- is there an attract mode that introduces users to the system?
examples
- video games
- theo's interactive story project