Format for Qualifier: Each student is to answer 5 questions in total.

At least three of those questions must come from the Part 1 and one question must come from Part 2. The remaining question can come from either section.

In providing your answers, please make sure to put your student ID number on the top of every page. Please also start each new question on a new page. When writing your answers, place relevant references that are cited in your answer at the end of the question.

1. Suppose you developed an e-retail clothing Web site.

a) Usability is important for a number of different stakeholders in this domain. Give three concrete and specific aspects of the Web site that would impact its usability and identify the stakeholder most directly concerned with that aspect.

b) Of the concrete aspects described above, pick one that could be evaluated through empirical user studies. Describe an experiment you would conduct to see how (or if!) these features affect "usability" (and make an argument for what aspects of usability are relevant here). Be sure to discuss the type of subjects, the tasks, the dependent measures, and other aspects of the experiment. Indicate why these things matter in your experiment and how you are manipulating or controlling them. Provide hypothetical results (not numbers, just performance differences) and indicate what they mean.

c) Now choose one of the concrete usability aspects that could be evaluated through some discount usability technique. Describe what technique you would choose and why that technique would be appropriate for the evaluation study. Discuss how the discount technique would need to be targeted for this particular evaluation exercise.

2. Models of human cognition (Model Human Processor, situated action, activity theory, distributed cognition) are useful tools to inform HCI research. The model can serve as a framework for guiding design and evaluation throughout the majority of the research process.

a) Briefly describe the breadth of ways that cognitive models can inform a particular project. Provide examples where possible.

b) In more depth, describe how one or more of these models could be used to frame/guide your past, current or future research.

3. In their classic graphics textbook, Foley et al. introduced a basic set of interaction tasks (positioning, selecting, entering text, entering numeric quantities) and composite interaction tasks (dialogue boxes, construction of objects with two or more positions, and object manipulation to reshape existing geometric objects. These seven interaction tasks formed the foundation for input toolkits to create graphical user interfaces. In their CHI '90 paper, Card, MacKinlay and Robertson formally defined a design space for input devices based on a 6-tuple defining the basic transducing operation of a primitive input technique and three composition operators (merge, layout and connection) to create more complex input devices. This input design space was used to categorize most of the existing input devices known in 1990 and also suggested a variety of new input devices that could be created. A more recent trend in the UIST community has been to invent more hardware- and sensor-based input technologies, which we will refer to under the collective name of tangible input technologies.

a) Discuss whether the Foley et al. and Card, MacKinlay and Robertson input classification techniques are still relevant when applied to these tangible input technologies.

b) What extensions would you propose to better classify tangible input technologies?

c) How might you modify the input system of a common UI toolkit architecture (such as MVC or another one that you are familiar with) to handle the specific characteristics of tangible interfaces. Make sure you consider tangible interfaces with haptic feedback.

4. The following three ways in which user intereface widgets that display information (like textboxes) can communicate with underlying domain objects:

- MVC: Domain objects "broadcast" when they have changed, and UI widgets ask the domain objects for state information.

- Polling: UI widgets that display information get regular CPU slices in which they can "poll" their domain objects for state information.

- Constraints: Objects external to either the domain objects or the UI maintain the relationship between these pieces. As UI changes or the domain changes, the constraint objects either poll or are informed of changes, and the constraints make sure the UI and domain objects maintain the desired relationship.

All three of these have been used in desktop applications. But let's consider some new domains for user interfaces, specifically PDAs and Web-based applications running thin clients that communicate with network servers. For both of these domains, discuss the pros and cons for each of these approaches for developing interfaces in the domain.

Which of these mechanisms is best in each domain?

5. One idea for a virtual assistant is that it "observes" your everyday activities and "provides" you relevant information to support your everyday routines.

a) What kind of information can the assistant observe and how can that information be collected with minimal distraction to the everyday routines?

b) How would you go about understanding what forms of support from the virtual assistant are useful for these everyday routines?

c) Choose a specific activity and specific support need. What modes of presentation are possible and appropriate for supporting a person as they perform the everyday activity?

6. Describe design guidelines for creating a peripheral display that provides a visualization of the activity of colleagues in your work environment. How would you evaluate the display to see if it met your guidelines?

7. Media Spaces: Significant research has been done to date on using two-way video and audio links to foster informal communication in workplace settings.

a) Review work done in this area to date: What motivated this line of inquiry? To what extent was it successful? (You may focus exclusively on relevant readings on the qual. list; going beyond the list to mention other studies you're familiar with is optional.)

b) What research questions in this area would benefit from further study? Outline the open questions, and identify which of those are most promising for further research. Explain your rationale in detail. Would answering those questions potentially benefit other HCI or CSCW areas, beyond informal workplace communication?

8. List three visualization techniques (not systems or tools) that are appropriate for multivariate data sets of 10-12 variables. What are the relative strengths and weaknesses of each technique, and what types of user tasks would each best facilitate?

9. Describe three well-known ubicomp systems from the literature that rely on capturing and recording human activity. Include examples from at least two different domains. Most of these systems do not incorporate any facility for forgetting captured activities. What are some motivations and strategies for incorporating forgetting into the systems you mentioned above?