Gabriel Spitz

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What Is The User Interface DesignLecture # 2

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Why a User Interface

Enable Enable the user to perform specific tasks Enable the user to acquire specific information

Communicate Communicate to the user what has to be done Communicate to users how it should be done

Promote Promote a positive experience Promote satisfaction

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What is the User Interface (UI) A user interface is the means and methods that we

provide to the users to achieve their goal

The user-interface always includes:o A concept of what the user is trying to achieve

o A goalo Process or flow - the sequence of steps by

which an intent can be achieved o How will it happen

o Mechanisms that are used to control and manipulating objects in the work area o In what way

o Language, images and controls used in communicating between the user and the applicationo Using what means

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Example of User Interfaces

Guiding User Behavior

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What is Included in the UI

User Interface includes more than the functionality it offers the user. It also includes Physical characteristics – Size, resistance Perceptual/Cognitive characteristics – Color, font

size, label, work flow Conceptual characteristics– What is this like

When designing a user interface we need to consider all of the above aspects

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User Interface Design

UI

Scope

Concept

Activity Flow

Representation

Presentation

Needs Experience

Predictability

Convenience

Efficiency

Personal

Trust

Human

Task

Expectations

Usefulness

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Interfaces are Everywhere

Interfaces are used in controlling or manipulating Products – PIM, Cell Phones, Cars, etc. Applications – Excel, Word, etc. Our environment – Thermostat, Appliances, etc.

Interfaces are the medium through which the user communicate with the computer application

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Controls

Displays

Procedure

Guidance-labels

UI Example

Watch

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UI Example

Telephone

Controls

Displays

Procedure

Guidance-labels

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UI Example

Controls

Displays

Procedure

Guidance-labels

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UI Example

Kiosk

Controls

Displays

Procedure

Guidance-labels

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Importance of the Interface

The “quality” of the interface design directly drives the user experience user attitude and feelings User satisfaction user performance safety

Poor user interface can have serious consequences

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Poor UI – Can Ruin an Election

Florida Ballots (2000)

Users could not figure out How to use –Poor mapping between stimulus & response

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Poor UI – Can Ruin your Dinner

Poor Mapping

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Poor UI – Can Ruin a Product

Bob

Microsoft 1995

Users simply did not like this interface –

User satisfaction

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Poor UI - Can be a Safety hazard

Negative transfer of training resulting in many errors

Renault 4 circa 1970

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Poor UI - Can Ruin a Trip

Lavatory sink – It is difficult to use Performance

Incompatibility between control design and task

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The Importance of Usable Interface

o From a user’s perspective there is no good user interface in the absolute sense only usable and useful interface

An interface is bad or good only to the extent that it hinders or supports users in performing a specific task in a specific environment Poor interface = Poor product/application

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What is a Usable Interface

Our goal is to design the user interface for products so they enable users to achieve their intentions in an easy and pleasant way

An interface is considered usable if it: Helps user achieve their goal Easy to learn Easy to use – e.g., recall vs. recognition, simple Facilitates performance – speed, errors Fun to use

These aspects of the interface are also called Usability Indicators

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Usability of an Airline Kiosk

Key usability indicators Goal achievement – to obtain a

boarding pass (but sometimes to get onto an earlier flight)

Learning - no learning required Ease of use – system leads users (hand

holding) Performance – not applicable (from

passenger perspective) Fun – nice to have, but not critical

Rarely can we maximize all of them