Conceptual Design

Define conceptual design in one sentence. (1)

Conceptual design is the process of turning user requirements into a clear, abstract conceptual model of the system’s functions, structure and information, before any decisions about how it will look or behave

What is task allocation?

The process of deciding what the system will do and what the user will do

What does conceptual design do? (3)

Transforms user requirements into a conceptual model; decides what functions the product performs and how they relate; decides what information needs to be available

What is conceptual design concerned with? (4)

Abstract descriptions of the system's logic; functions; structure; content

What is physical design concerned with? (3)

Who does what (allocation of functions); how artefacts look; how artefacts behave

What is the minimum system specification? (3)

A conceptual model; a set of use cases; a design language

What is a mental model? (1)

The understanding and knowledge a person holds of something (Norman, 1998)

What happens if people have a poor mental model? (3)

They can only perform actions by rote; they will not know why something goes wrong; they will not be able to recover

How do people develop mental models? (3)

Through interacting with systems; by observing the relationship between their actions and system behaviour; by reading manuals or other explanations

What must designers provide so users form an accurate mental model? (2)

Sufficient information in the interface; sufficient information in any accompanying documentation

What is a conceptual model? (2)

The model designers want users to understand; users' mental models should be close to the one designers intended

How does a conceptual model describe a system? (3)

Abstractly, in terms of tasks; what users can do with the system; what concepts users need to be aware of (not keystrokes, mouse actions or screen graphics)

What are the goals of a conceptual model? (2)

Keep it as simple as possible with few concepts; focus it on the task domain with no concepts users must master that are outside it

Why design the conceptual model before the user interface? (1)

The application will be cleaner, simpler and easier to understand

Why create a conceptual model? (4)

Helps the team use common terms; reduces misunderstandings and confusion; avoids a narrow early focus; orients users

How does a conceptual model differ from a user interface? (2)

It is not a description of the interface; it is a structure outlining concepts and the relationships between them

What are the three questions conceptual design answers? (3)

What functions will the product perform; how are the functions related to each other; what information needs to be available

What is task allocation? (3)

Deciding what the system will do; deciding what the user will do; has considerable social implications

What does considering function relationships involve? (3)

Whether an order or pattern is required; whether there is a fundamental categorisation of functions; using task analysis to support the decision

What is task analysis? (2)

Supports decisions about how functions relate; shows the subtasks involved and the order they are performed in

What does considering information requirements involve? (3)

What data are required to perform a task; how the data need to be transformed; the nature of the data often determines elements of the system design

What are the components of a conceptual model? (5)

Metaphors and analogies; interaction mode styles and task allocation; concepts users are exposed to; relationships between the concepts; mappings between the concepts and the user experience supported (temporal ordering)

What is a metaphor in design? (2)

Taking concepts from a source domain (vehicle); applying them to a target domain (tenor) to describe something new in familiar terms

What are the benefits of interface metaphors? (3)

Make learning new systems easier; help users understand the underlying conceptual model; tap into users' existing experience (a training multiplier)

What are the problems with interface metaphors? (5)

Break conventional and cultural rules; constrain how designers conceptualise the problem space; force users to understand the system only through the metaphor; can transfer bad parts of existing designs; limit designers' imagination for new conceptual models

What must be true of a good metaphor? (2)

It must be a good match to the real system; otherwise there can be undesirable consequences

What are the four interaction mode styles? (4)

Instructing; conversing; manipulating; exploring

What is the instructing style? (3)

Users instruct the system about what to do; supports quick and efficient interaction; good for repetitive actions on multiple objects

What is the conversing style? (4)

Underlying model of a conversation with another human; ranges from simple voice menus to natural language dialogue; familiar for novices and people with negative attitudes; misunderstandings arise when the system cannot parse what the user says

What is the manipulating style? (2)

Dragging, selecting, opening, closing and zooming actions on virtual objects; exploits users' knowledge of how they move in and manipulate the physical world

What are the features of direct manipulation? (4)

Continuous representation of objects and actions of interest; physical actions and button pressing instead of complex commands; rapid reversible actions with immediate feedback; what you see is what you get (WYSIWYG)

What are the advantages of direct manipulation? (5)

Easy to learn for new users; efficient for experienced users; easy to remember for intermittent users; results of actions are seen immediately; users feel in control

What are the disadvantages of direct manipulation? (3)

Not all tasks can be described by objects or done directly; some tasks are better achieved through delegating; using a mouse can be slower or harder than pressing keys

What is the exploring style? (2)

Similar to how people browse existing media; information is structured for flexibility and the user can search for it

When should each interaction style be chosen? (3)

Direct manipulation for 'doing' tasks; instructing for repetitive tasks; conversing for children, computer-phobic or disabled users, specialised applications or fun

What are hybrid conceptual models? (2)

Support different ways of carrying out the same actions at the interface; can take longer to learn

How do you add an image in HTML? (3)

Use the img inline element; the src attribute holds the URL; the alt attribute describes the image contents

How do you size an image? (1)

Use the width and height properties in CSS

How do you add audio in HTML5? (3)

Use the audio element; the src attribute gives the source URL; Boolean attributes autoplay, controls and loop can be added

What does the loop attribute do? (1)

Makes the audio or video repeat continually from beginning to end

How do you add video in HTML5? (3)

Use the video element in place of audio; the same attributes and fallbacks apply; a poster attribute can supply a preview image