Interaction Model

1. Interaction Model

2. User Perspective • User-centered design sounds good and as the right thing to do • But • What does it mean to design something from a users’ perspective • How do users view the interface

3. Norman’s Activity Model • Don Norman (1988) proposed that users view the user-interface as a mean to an end • The interface, according to Norman’s model provides users with the mechanisms to achieve something that they desire or want • This mechanism includes 2 basic elements of the interface • Interface – How it communicates to user what to do or what can be done • Interaction – Describes what users are expected to do

4. User Interface Design • For example • The interface includes: • The blue icon • Message • Labeled button • The interaction with the error message box below consist of: • Reading the message • Clicking on the close button

5. Norman’s Action Model • Norman’s activity model deals with the interaction • Norman suggested that people’s action includes 3 components: • An Intention • An action • An Evaluation • Actions are performed within a context of a higher level goal

6. Example – removing The Error Message • To remove the error message (Goal) the user will • Express an intent to close the message • Click on the “Close” button • Check to make sure that the dialog box is indeed closed

7. Activity Model Goal Gulf of Execution Gulf of Evaluation External World

8. Gulf of Execution • Deals with the gap between what the user wants to do – Intention and the action needed to implement the intent • How do I start my car • How do I save a document • How do I set the time on my car clock • A gap exists when users have difficulties determining how to act

9. Gulf of Evaluation • Deals with the gap between perception and interpretation • Did my car started? • Was my document saved? • Am I controlling the time on my car clock? • A gap exists when users have difficulties Assessing the state of their system - determining what happened in the real world

10. Implementing the Action • For users to close the gaps they will need to • Execution • Form an intention • Plan out the action flow • Execute the plan • Evaluation • Perceive the result • Interpret the result • Evaluate the result

11. Closing the Gaps Goal Intention Comparison Detailed Plan Interpretation Execution Perception External World

12. Example - Execution • Forming a Goal • I want to inform my team about a meeting I had. • Intention to Act • I have outlook open on my desktop. I will set up a meeting for the team and myself. I will open a meeting invitation • Planning the Action • I need to move the cursor to the meeting icon and click on it • Executing the Action • I move the cursor to the meeting icon and I click on it

13. Example - Evaluation • Feedback from the Action • A meeting set up form is opened • Interpret the Feedback • I am now able able to specify a meeting and invite Sean • Evaluate the Outcome • Positive – I’m able to start scheduling a meeting. No further action is needed • Negative – The form I opened is for scheduling an appointment not a meeting • The Action Cycle is either repeated or a new goal is formed

14. From Michael J. Darnell @ http://www.baddesigns.com/

15. Example – Execution Challenge