Light Switch Issues

1. Gabriel Spitz

2. Gabriel Spitz Light Switch Issues • Consistency – The switch design is inconsistent with common light switches • Visibility – No visible cue regarding on/off operation • Affordance – The switch design does not suggest how should it be operated

3. Gabriel Spitz How do people use an Interface Lecture # 4

4. Gabriel Spitz User Interface Design? • Design is solving a problem • Design is creating an object or the means to enable, in our case a user, to achieve an intent • To optimize our solution we need to understand how people interact with the world

5. Gabriel Spitz Human Action Intent Refine/Stop Assess Plan Act

6. Gabriel Spitz 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 • An Interface – The means used to communicates between the user and application what needs to be done • Interaction – The mechanism by which the user is expected to achieve the tasks using the interface

7. Gabriel Spitz User Interface Design • For the example below • The interface includes: • The blue icon • Message • Labeled button • The interaction includes: • Reading the message • Clicking on the close button

8. Gabriel Spitz The Action Model • The action model deals with the interaction • It suggests that the way people act can be decomposed into: • An Intention • A Plan • An action • An Evaluation • Actions are performed within a context of a higher level goal

9. Gabriel Spitz Example – Removing The Error Message • To remove the error message (Goal) the Activity Model hypothesizes that user will • Formulate an intent to close the message • View the box and decide that to close it one needs to click on the close button • Click on the “Close” button • Check to make sure that the dialog box is indeed closed

10. Gabriel Spitz Activity Model Goal Evaluation Gap How do I (the user) affect the state of the world Was the change that I sensed the same as what I expected Execution Gap External World

11. Gabriel Spitz 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 • The role of the user interface is to help bridge this gap by helping users determe how to act

12. Gabriel Spitz 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? • The role of the user interface is to help user determine what happened in the real world

13. Gabriel Spitz Implementing the Action • For the user Interface to be effective it will need to assist users in helping them • Execution • Form an intention • Plan out the action – how will it flow • Execute the plan • Evaluation • Perceive the result • Interpret the result • Evaluate the result

14. Gabriel Spitz Veering to the Left of the Road • Form an intention • Plan out the action • Execute the plan • Perceive the result • Interpret the result • Evaluate the result

15. Gabriel Spitz Closing the GapsHelping the user cross the chasm Goal Intention Comparison Detailed Plan Interpretation Execution Perception External World

16. Gabriel Spitz 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

17. Gabriel Spitz 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

18. Gabriel Spitz Example – Planning Challenge From Michael J. Darnell @ http://www.baddesigns.com/

19. Gabriel Spitz Example – Planning Challenge

20. Gabriel Spitz Example – Execution Challenge

21. Gabriel Spitz Example – Interpretation Challenge

22. Gabriel Spitz So what are the the implication of this model for design?