Conceptual Model DesignInforming the user what to do

Lecture # 10 (a)

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Interface elementsInterface aspects

Application Component

Info Space Control

Function/Scope Available functions Missing & superfluous functions

Completeness TBD

Framework Organizing principle (Posture)Segmentation into components

Segmentation into info spacesGrouping of itemsProximitySequencing items

TBD

Activity flow/Behavior Navigation schemaTask sequenceError recoveryAction reversalSystem state info

Action constraints (error avoidance) GuidanceSpatial workflowModes/temporal workflow Closure

FeedbackDefaultsShortcuts

Representation Metaphors / expressionsIdioms

Strategy (e.g.) FormWizardMessage content (error, warning, information)Maintaining context

Choice of controlLabels/terminologyIcon contentObject manipulation methodAffordance

Presentation Color Pallet TypographyPreferences

LayoutAlignmentRepetitionContrast

ColorFont styleGraphical clarity (of icons) Resolution (details) Manipulation dynamics

Interface Design SpaceGabriel Spitz

Exercise

Describe the route you take to get from home to UMB

Where is the description coming from

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Helping the User Figure It Out

Our action is driven by what we see and how close is what we see to what we expect/know

What we see is the Conceptual Model of the interface

What we expect is our Mental Model of the interface

We as UI designers are responsible for selecting and implementing the conceptual model of our design

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Conceptual Model VS. Mental Model

• Conceptual model is a mental representation of how an artifact works & how the interface controls affect it. It is the way the user will understand the interface

• Mental model is the idea a user has about an interface – Mental representation

• The closer a conceptual model is to the mental model the easier it is for a user to figure out how to operate a system

Me

Mental Model of a BicycleConceptual Model of a Design

A. Cooper’s Conceptual Models

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Manifest Model = Conceptual Model or Framework

Mismatch Between Models

Mismatch between the users’ expectation – their mental model; and the conceptual model used by the UI designer will lead to: Error Poor performance Frustration

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7

A Conceptual Model

Is the way the system will appear to users and therefore the way the user will understand it

It is the overall “big idea” of the UI For example this interface is like a desktop, a wending

machine, an ATM machine

It is also the context within which UI elements – actions & components – are anticipated and interpreted

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Conceptual Models Examples

Two Panel Concept

Two panels side by

side. One shows the

set of items

user can select

from, the other

shows the content of

the selected

item

This is a learned

interaction, but very

common and quick to learn

Tabular Concept

List Concept

Content Group

Form Concept

Creating a Conceptual Model

Conceptual models are created by our choices for the interface Interaction styles – The Activity/Method we use for

the interaction The metaphor – The object we interact with

Keep in mind that the interface has to communicate how it should be used Help information can aid, but should not be

necessary

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Interaction Styles

Interaction styles refers to the way we interacts with an application. These include: Instructing Conversing Manipulation Browsing & Navigating

Metaphor or the objects used in the the interaction such as Blank sheet of paper Spreadsheet Canvas

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Instructing (activity)

Instruction is common conceptual model in user-interface and used by many applications Instructing is performed using keyboard commands,

function keys, menu items, etc.

Instructing refers to telling the system to perform specific tasks such as Print, save, delete, etc.

The main benefit of instruction is that it supports quick and efficient interaction Good for repetitive actions performed on multiple objects

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Instructional Style Interaction

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Conversation (activity) The underlying model of this interaction mode is a

conversation with another human

Users ask and the system responds

Examples include: Help Facilities Search Engines Interactive Voice Recognition –Siri

The benefit of this interaction style is that it allows users to interact with the system in a way that is familiar Makes them feel comfortable, at ease and less scared

The drawback is that misunderstandings can arise when the system does not know how to parse what the user says

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Conversational Style Interaction

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Direct Manipulating (activity)

Involves dragging, selecting, opening, closing and zooming actions on virtual objects

Exploit’s users’ knowledge of how they move and manipulate objects in the physical world what you see is what you get (WYSIWYG) the direct manipulation approach (DM)

Shneiderman (1983) coined the term Direct manipulation

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Core Principles of DM

Continuous representation of objects and actions of interest

Physical actions and button pressing instead of issuing commands with complex syntax

Rapid reversible actions with immediate feedback on object of interest

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Benefits of DM Interfaces

Easy to learn basic functionality

Users can work rapidly to carry out a wide range of tasks

Easy to remember how to carry out tasks over time

Easy to detect errors

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Disadvantages of DM

Some people take the metaphor of direct manipulation too literally

Not all tasks can be described by objects and not all actions can be done directly

Some tasks are better achieved through delegating • e.g. spell checking

Can waste extensive screen space

Moving a mouse around the screen can be slower than pressing function keys to do same actions

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Direct Manipulation Interface

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Exploring and Browsing

The way people browse information with existing media (e.g. newspapers, magazines, libraries, pamphlets)

Information is structured to allow flexibility in the way a user is able to search for information e.g. multimedia, web

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Object Based Conceptual Models

Usually based on an analogy with something in the physical world

Examples

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