HCI Research Project

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

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

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?

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?

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?

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

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

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

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.

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

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?

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)

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

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

Organization  Teams of two or three –Membership approved by instructor –Members choose leader

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

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

Research Ideas

Turning Issues into Research 1. Need earlier prompts with some car navigation systems 2. Help systems need to be helpful 3. Should order of input matter? 4. Should the system respond after it receives input from the user? 5. Speech recognition systems are poor, not very accurate

Issues into Research (2) 6. Time delays in responding to input are annoying, may have high error cost. 7. Controls should match mental models 8. Systems should display current data and use a continuous update strategy 9. Error messages should make sense to the user.

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 interface support task management?

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?

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?

Sources for More Ideas  CHI Conference Proceedings  ACM Transactions on HCI  Course web site