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 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.