Note: This was published in ACM Interactions, volume 15, issue 5. Everyone wants simplicity. The same desires are there whether the device be a new cellphone or a shop tool, the dashboard of an automobile or the choices while shopping in a store. "Why can't my technology be as easy to use as my garage door opener?" asks one paper on the topic: "one button and it opens or shuts the door. Simple, el

Note: This was published in ACM Interactions, volume 15, issue 6. It is time for a review. As time and technologies change, as we have moved from individual to group, social, and even cultural computing, and as the communication technologies have become as important as the computational ones, how well have our design principles kept up? One of our fundamental principles is that of perceived afford