Lecture 6: HCI, advanced course, Design rationale for HCI

Transcription

1 Lecture 6: HCI, advanced course, Design rationale for HCI To read: Carroll, J. M., & Rosson, M. B. (2003) Design Rationale as Theory. Ch. 15 in J.M. Carroll (Ed.), HCI Models, Theories, and Frameworks. San Francisco: Morgan Kaufmann

2 Outline What is Design rationale What is the purpose? How is it conducted? Contributions to HCI research Design rationale 2

3 What is Design rationale? Rationale has to do with logical explanations and reasons Discussions, debates, negotiations Reasons for features Reasons against features Weighing of tradeoffs Design rationale 3

4 Why Design rationale in HCI Increase understanding interaction situations by documentation analysis descriptions consequences Showing important aspects context applicability scope Design rationale 4

5 Tools used in Design Rationale scenarios narratives claims analysis DR supports task-artifact framework Design rationale 5

6 Scenarios describe user interaction made-up or observed situations documented as narratives several scenarios are recommended Design rationale 6

7 To identify scenarios typical scenarios from theory observation, field studies personal experiences documented experiences we look for situations where contradictions are obvious Design rationale 7

8 Claims analysis Claims are statements that are carefully scrutinized every claim is associated with benefits and drawbacks, systematically documented decisions are supported by theories relevant for the current situation Design rationale 8

9 Example News on the web: + a virtual newspaper is a good means to provide some information to the users. + it can help the user to think that he/she is in a community. - but the actual text-form is not readable without scrolling a lot. - but with a web-interface, it's really not easy to look at that Design rationale 9

10 How to find claims Text analysis Pose questions related to situations/actions/goals what made her click there? Use Norman s stages of action Analyse scenarios with users Design rationale 10

11 Norman s stages of action Forming the goal Forming the intention Specifying an action Executing the action Perceiving the state of the world Interpreting the state of the world Evaluating the outcome Design rationale 11

12 Evaluation Goals Execution Evaluation of Interpretations Interpreting the Perception Intention to Act Sequence of Actions Perceiving the State of the World Execution of the action sequence The World Design rationale 12

13 Ecological approach in HCI-research what does it mean? something develops over time, adapts to certain circumstances emphasis on viewing a system in a context compare it to ecological validity Design rationale 13

14 Ecological approach Three levels taxonomic science design science, DR as raw material evolutionary science, taskartifact cycle decisions are described causal relationships become visible Design rationale 14

15 Task-artifact cycle requirements tasks artifacts possibilities Design rationale 15

16 Action research Observation and improvement combined Reactions are studied Focus on strategies for change Simplifies the research process, no need to transfer knowledge Design rationale 16

17 Synthetic science One single theory is not enough for interaction design Find trade-offs, could be perceptual, psychological as well as sociological aspects No theory considered more valuable than another, all can be applied in Design rationale Design rationale 17

18 The design process Choose analysis method data gathering analysis phase conceptual design/design implementation/ prototype evaluation Design rationale 18

19 Summary Design rationale at several levels: a tool for communicating design alternatives/decisions to users or clients contributes to general design knowledge supports research approaches contributing to HCI theory Design rationale 19