The State of Maryland is developing a web-voting interface. For selecting the candidates, one design (RB) is a set of radio buttons and another is (CB) a combo-box (drops down when selecting the scroll arrow icon), both using standard fonts at 10-point size. Compare these two designs when there are 4 candidates and predict the relative speed of performance and error rates. Support your choice by a thoughtful argument. An expert reviewer complains that both designs may work with young users who are familiar and expert in using a mouse, but that there will be problems for elderly and motor impaired users who have difficulty controlling a mouse. The reviewer recommends a new design (UU) that includes a larger font (20-point size) and a numbered list to allow selection by keyboard easily. Describe a Participatory Design or Social Impact Statement process that might clarify this issue with elderly users. Design an experiment to help resolve the issue brought up in Question 3. Assume you have substantial resources and access to subjects. Provide a definition of participatory design. Give three arguments for and three arguments against participatory design. Draw a sketch of the three pillars of successful user-interface development. Also provide a brief description of each pillar. Consider a system that does not yet exist. An exmple is a totally authomated fast-food restuarant, where customers order via touch screen interactions, pay by swiping their debit or credit cards, and then pick up their foodanalogous to the self-check-out at some supermarkets, but even more extreme. Discuss how you conduct a contextual inquiry for a system that does not yet exist. CASE STUDY: Evaluate an existing system where you would propose improvements to the user interface. For example, visit the local mass transit station (e.g., the subway) and observe users purchasing tickets. If possible, interview users regarding their preferences for improvements in usability. One method to facilitate user cooperation may be to solicit fellow students or colleagues who are new to your community and have not yet taken a ride on the subway system. Plan for contextual interviews by developing questionnaires. Conduct the contextual interviews, then tabulate the results and analyze them with an eye to understanding the demographics and skills of the user community. Then follow the remaining steps outlined in this list, eventually developing storyboards and prototypes to evaluate with users.