because the things people do everyday become habitual and unconscious, people usually are unable to articulate their work practice. therefore, in order to get accurate and situated user behavior data, we conducted contextual inquiry interviews at sit-down restaurants, during the group bill-splitting activity.

to obtain a broader picture of the bill-splitting ecology we not only interviewed customers but also servers and a manager. we asked them to think outloud and walk us through the activity as they were performing it.

within 24hrs of the interview, we came together as a group to run an interpretation session. the interviewer shares with the rest of the team, while another member captures all relevant information, including emotion and breakdowns in the workflow.

the interview interpretation notes are then written on "post-it" notes. the notes are used to parse and categorize the massive amount of data and discover user needs and design opportunities. these notes are organized on an affinity diagram/wall.

building the affinity wall is an inherently social task, as group members are given free-range to categorize the affinity wall until a universal consensus is reached.

another product from the interpretation sessions are work models, which are diagrams that capture the physical and temporal structure of the users' activity and help identify breakdowns, and design opportunities

there are 3 types of work models: 1. physical models, which represent physical environment. 2.sequence models, which is a step-by-step recording of the tasks observed or retrospective accounts recorded and 3. artifact models, which are copies or representations of all the artifacts used.

affinity notes can also be written with information from the work models

to become familiar with the sheer amount of behavior data the team members walked the affinity wall and the work models. as the team member walked through the data, he or she, could write a design idea and place it next to the part of the wall that generated the idea.

afterwards, as a group we defined key issues, design opportunities and hot design ideas.

visioning is the initial synthesis of all this work. it was our opportunity to envision our solution for the bill-splitting problem according to our findings.

after visioning, we created paper prototypes of our redesigned bill and order form. each paper prototype was tested in context, either in situ at a restaurant or by role playing. much like the contextual inquiry interviews, we observe users interact with the paper prototype. a huge benefit of paper prototypes is the quick iteration of designs according to the findings of each protype testing session.

the showpiece of our project was a redesigned bill, with perforations and a sticky strip that allow customers to physically split the bill and append their portion to their individual payment types.