how do people use an interface
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How do people use an Interface. Lecture # 4. 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 . Human Action. - PowerPoint PPT PresentationTRANSCRIPT
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How do people use an Interface
Lecture # 4
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User Interface Design?Design is solving a problemDesign is creating an object or the means to
enable, in our case a user, to achieve an intentTo optimize our solution we need to understand
how people interact with the world
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Human ActionIntent
Plan
Act
Assess
Refine/Stop
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Norman’s Activity ModelDon Norman (1988) proposed that users view the
user-interface as a mean to an endThe 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
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User Interface DesignFor the example below
The interface includes:The blue iconMessageLabeled button
The interaction includes:Reading the messageClicking on the close button
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The Action ModelThe action model deals with the interactionIt suggests that the way people act can be
decomposed into:An IntentionA PlanAn action An Evaluation
Actions are performed within a context of a higher level goal
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Example – Removing The Error Message
To remove the error message (Goal) the Activity Model hypothesizes that user willFormulate an intent to close the messageView the box and decide that to close it one needs
to click on the close buttonClick on the “Close” buttonCheck to make sure that the dialog box
is indeed closed
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Activity ModelGoal
External World
Execution Gap
Evaluation GapHow do I (the user) affect the state of the world
Was the change that I sensed the same as what I expected
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Gulf of ExecutionDeals with the gap between what the user wants
to do – Intention and the action needed to implement the intentHow do I start my carHow do I save a documentHow 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
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Gulf of EvaluationDeals with the gap between perception and
interpretationDid 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
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Implementing the ActionFor the user Interface to be effective it will need
to assist users in helping them Execution
Form an intentionPlan out the action – how will it flowExecute the plan
EvaluationPerceive the result Interpret the resultEvaluate the result
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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
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Closing the GapsHelping the user cross the chasm
Goal
Intention
Detailed Plan
Comparison
Interpretation
Perception
External World
Execution
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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
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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
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Example – Planning Challenge
From Michael J. Darnell @ http://www.baddesigns.com/
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Example – Planning Challenge
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Example – Execution Challenge
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Example – Interpretation Challenge
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So what are the the implication of this model for design?