HCI Research Project

1. HCI Research Project

2. Research Paradigms Theoretical (in the style of mathematics) • Mathematical deduction • Simulation • Analysis of algorithms The researcher: • Checks many examples • Conjectures a result in the form of a theorem • Constructs the proof of the theorem from known results

3. Research Paradigms (2) Experimental (in the style of psychology) • Hypotheses checked with controlled experimentation The researcher: • Poses hypotheses • Extensive background reading • Appropriate theoretical model • Conducts controlled experiments • Performs statistical analysis of data • Draws conclusions

4. Sample Research Questions • Why don’t typical users invoke advanced search strategies? • What is the preferred method of making a choice from a lengthy list? Note behavior of scroll bar, key index • What is the best semantics for the Tab key operating on a Web form? • What is the best shopping cart checkout design?

5. Sample Research Questions (2) • What features should pie menus have in a gesture-based interface? • How should information scent be shown on search reports? • What intelligent agents are most helpful in a tiny interface? • What ZUI widgets are most helpful for information retrieval?

6. Questions to Hypotheses • Key is measurability • Identify • Independent variable(s): those things the researcher can control • Dependent variables: those things the researcher can measure • Aside: What is measurable?

7. Measuring Things • Objectively • Time: to do, to correct, to learn • Counts: tasks performed, errors made • Distance, or other geometrical attributes • Text: density, complexity, reading level • Images: size, color • Subjectively • Preference • Rating scale

8. Good Experimental Design • Limit number of independent variables • Limit number of values for each independent variable • Make dependent variables easy to measure • Develop good working definitions • Control for external bias • Guard against learning and practice

9. Good Experimental Design (2) • Base hypotheses on theoretical model • Phrase hypotheses in measurable terms • Choose subjects representative of larger group

10. Example 1 From Goren-Bar, What Do Users Prefer Hypothesis 1: …. users in general will find the user-oriented search method as more suitable for searching the web, compared to search methods that do not consider the user perspective.

11. Example 1 (continued) Hypothesis 2: Novice and knowledgeable users will not have the same response to both search approaches.

12. Example 2 From St. Amant, … Navigation and Intelligent Assistance Assume that the precision and recall of an intelligent assistant can be controlled. Hypothesis 1: Is any assistance better than no assistance?

13. Example 2 (continued) Hypothesis 2: Does task performance change with the precision of the assistance? (Precision = proportion of assistance that is relevant) Hypothesis 3: Does task performance change with the recall of the assistance? (Recall = proportion of relevant information that is provided)

14. Example 3 From Basgodan, Touch in Shared Virtual Environments Hypothesis: Touch is an essential element in performing a task in a shared virtual environment.

15. Human Subjects • Informed consent • Minimized risks • Institutional Review Board (IRB) • Expedited review • Application form

16. Organization • Teams of two or three • Membership approved by instructor • Members choose leader

17. Items to be Submitted • Initial phase • Team membership preferences • Hypotheses, independent and dependent variables • Bibliography • IRB approval form—includes experimental design and materials • Oral presentation of project

18. Items to be Submitted (2) • Investigative phase • Progress reports as required • Final phase • Draft of Introduction, Background and Theoretical Foundation • Draft of Results, Analysis, Conclusion • Final report: oral and written • Poster abstract and design

19. Research Ideas

20. Turning Issues into Research • Need earlier prompts with some car navigation systems • Help systems need to be helpful • Should order of input matter? • Should the system respond after it receives input from the user? • Speech recognition systems are poor, not very accurate

21. Issues into Research (2) • Time delays in responding to input are annoying, may have high error cost. • Controls should match mental models • Systems should display current data and use a continuous update strategy • Error messages should make sense to the user.

22. Research Questions • What is the task analysis of purchasing an airplane ticket? How well is it supported by an airline website as displayed on a smart phone? • How should a PDA support a shopping list? • How can an email interface support task management?

23. Questions (2) • How do people manage their digital photographs? • What is the best interface for a GPS-based navigation system? • What are the features of a good proximity-aware recommender system?

24. Questions (3) • What design features promote the success of reprogrammable keys? Or of soft keyboards? • How fast should automatic scrolling of information on limited size screens proceed?

25. Sources for More Ideas • CHI Conference Proceedings • ACM Transactions on HCI • Course web site