How do people use an Interface Gabriel Spitz 1

User Interface Design?  Design is solving a problem  Design is creating an object or the means to enable users to achieve an intent  And to do create a good solution we need to understand how people interact with the world Gabriel Spitz 2

Human Action Gabriel Spitz 3

4 Plan Act Asses Refine (if needed) Intent

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 Gabriel Spitz 5

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 Gabriel Spitz 6

The Action Model  The action model deals primarily 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 Gabriel Spitz 7

Example – Removing The Error Message Gabriel Spitz 8 What would be the cognitive steps to remove the message

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 Gabriel Spitz 9

Activity Model Gabriel Spitz 10 Goal External World Execution Gap 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

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 determine how to act Gabriel Spitz 11

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 Gabriel Spitz 12

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 Gabriel Spitz 13

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

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

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 Gabriel Spitz 16

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 Gabriel Spitz 17

But UI is Not Always Perfect Gabriel Spitz 18

Example – Planning Challenge Gabriel Spitz 19 From Michael J. Where do I go ?

Example – Planning Challenge Gabriel Spitz 20 How do I quit ?

Example – Execution Challenge Gabriel Spitz 21 What do I click on?

Example – Interpretation Challenge Gabriel Spitz 22 Where went wrong ?

So what are the the implication of this model for design? Gabriel Spitz 23