REQUIRMENTS REQUIRMENTS GATHERING:GATHERING:

knowledge of user knowledge of user interface and interface and

designdesign

Contents:Contents:

1.1. Introduction: The two types of Introduction: The two types of knowledge needed for user interface knowledge needed for user interface designdesign

2.2. Four psychological principlesFour psychological principles3.3. Three principles from experience: Three principles from experience:

Visibility, affordance, and feedbackVisibility, affordance, and feedback4.4. Design principles and design rules: Design principles and design rules:

knowledge for user interface designknowledge for user interface design

1 - Introduction: The two 1 - Introduction: The two types of knowledge needed types of knowledge needed for user interface designfor user interface design

““Design principles” are abstract, high-Design principles” are abstract, high-level guidelines – difficult to applylevel guidelines – difficult to apply

““Design rules” are low-level, highly Design rules” are low-level, highly specific instructionsspecific instructions

2 - Four psychological 2 - Four psychological principlesprinciples

Users see what they expect to seeUsers see what they expect to see Example: OK vs. CancelExample: OK vs. Cancel

Example:Example:

The principle of consistencyThe principle of consistency The principle of exploiting prior knowledgeThe principle of exploiting prior knowledge

2 - Four psychological 2 - Four psychological principlesprinciples

Users have difficulty focusing on more Users have difficulty focusing on more than one activity at a timethan one activity at a time MultitaskingMultitasking Cocktail party phenomenonCocktail party phenomenon

The principle of perceptual organizationThe principle of perceptual organization The principle of importanceThe principle of importance

2 - Four psychological 2 - Four psychological principlesprinciples

It is easier to perceive a structured layoutIt is easier to perceive a structured layout The law of proximity - we group things that are close The law of proximity - we group things that are close

togethertogether The law of similarity - shape, color, or formatThe law of similarity - shape, color, or format The law of closure - we tend to fill in the gapsThe law of closure - we tend to fill in the gaps The law of continuity - we look for patternsThe law of continuity - we look for patterns The law of symmetry - we look for symmetrical The law of symmetry - we look for symmetrical

bordersborders Figure-ground segregationFigure-ground segregation

2 - Four psychological 2 - Four psychological principlesprinciples

It is easier to recognize something than It is easier to recognize something than to recall itto recall it Example: grocery listExample: grocery list Knowledge in the head and in the worldKnowledge in the head and in the world Principle of recognitionPrinciple of recognition

3 - Three Principles From 3 - Three Principles From Experience: Visibility, Experience: Visibility, Affordance, and FeedbackAffordance, and Feedback

The principle of visibility: it should be The principle of visibility: it should be obvious what a control is used forobvious what a control is used for

3 - Three Principles From 3 - Three Principles From Experience: Visibility, Experience: Visibility, Affordance, and FeedbackAffordance, and Feedback

The principle of affordance: it should be The principle of affordance: it should be obvious how a control is usedobvious how a control is used

3 - Three Principles From 3 - Three Principles From Experience: Visibility, Experience: Visibility, Affordance, and FeedbackAffordance, and Feedback

The principle of feedback: it should be The principle of feedback: it should be obvious when a control has been usedobvious when a control has been used

4 - Design Principles and 4 - Design Principles and Design Rules: Knowledge Design Rules: Knowledge for User Interface Designfor User Interface Design

Design principlesDesign principles Visibility, affordance, feedbackVisibility, affordance, feedback

Design rulesDesign rules Exercise 5.3 – look for standardization in Exercise 5.3 – look for standardization in

the Microsoft Office XP software suitethe Microsoft Office XP software suite Commercial style guidesCommercial style guides

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