Design Rules (HCI)

Principles of usability

It pertains to the general understanding of the design rules.

Appearance

The _______________________ of the object stimulates a familiarity with its behavior.

Effectiveness

The accuracy and completeness with which specified users can achieve specified goals in particular environments.

Principles for usability

The success of designing for usability requires both creative insight (new paradigms) and purposeful principled practice.

Design rules

These are rules a designer can follow in order to increase the usability of the eventual software product.

Operation visibility

This refers to how the user is shown the availability of operations that can be performed next

Synthesizability

Ability of the user to assess the effect of past operations on the current state.

Design patterns/ Patterns

An approach to capturing and reusing this knowledge - of abstracting the essential details of successful design so that these can be applied again and again in new situations.

Design patterns

It captures and reuses design knowledge.

Satisfaction

The comfort and acceptability of the work system to its users and other people affected by its use.

Consistency

This pertains to likeness in input/output behaviour arising from similar situations or task objectives

Task migratability

This states passing responsibility for task execution between user and system.

Guessability and affordance

What is the related principle with familiarity?

Operation visibility

What is the related principle with predictability?

Immediate/ eventual honesty

What is the related principle with synthesizability?

Interleaved multi-threading

A type of multithreading permits a temporal overlap between separate tasks, but instructs that at any given instant the dialog is restricted to a single task.

Concurrent multi-threading

A type of multithreading which allows simultaneous communication of information pertaining to separate tasks.

Exploit the power of constraints, both natural and artificial (Norman's Seven Principles for Transforming Difficult Tasks into Simple Ones)

Constraints are things in the world that make it impossible to do anything but the correct action in the correct way. A simple example is a jigsaw puzzle, where the pieces only fit together in one way. Here the physical constraints of the design guide the user to complete the task.

Adaptivity

Decisions for this can be based on user expertise or observed repetition of certain task sequences.

Customizability

Defined as modifiability of the user interface by user (adaptability) or system (adaptivity)

When all else fails, standardize (Norman's Seven Principles for Transforming Difficult Tasks into Simple Ones)

If there are no natural mappings then arbitrary mappings should be standardized so that users only have to learn them once.

Soft

In the design of a graphical user interface, it is implied that a _________ button used in a form's interface suggests it should be pushed.

ISO 9241

It defines usability as effectiveness, efficiency and satisfaction with which users accomplish tasks

Guidelines

Tends to be lower in authority and more general in application.

Efficiency

The resources expended in relation to the accuracy and completeness of goals achieved.

Principles

These are derived from knowledge of the psychological, computational and sociological aspects of the problem domains and are largely independent of the technology.

Style guides

These are detailed guidelines applicable during later life cycle activities

Guidelines

These are less abstract and often more technology oriented, but as they are also general, it is important for a designer to know what theoretical evidence there is to support them.

Guidelines

These are more suggestive and general. There are many textbooks and reports that are full of these. Involves understanding justification for these aids in resolving conflicts

Standards

These are set by national or international bodies to ensure compliance by a large community of designers standards require sound underlying theory and slowly changing technology.

Standards

These are specific design rules, high in authority and limited in application

Using design rules

These are standards and guidelines to direct design activity.

Design patterns/ Patterns

They capture the essential common properties of good design: they do not tell the designer how to do something but what needs to be done and why.

Standards

They carry a much higher level of authority, it is more important that the theory underlying them be correct or sound.

Principles

They depend to a much greater extent on a deeper understanding of the human element in the interaction.

Design patterns/ Patterns

They represent design knowledge at varying levels, ranging from social and organizational issues through conceptual design to detailed widget design.

Browsability

This allows the user to explore the current internal state of the system via the limited view provided at the interface.

Defaults

This can assist the user by passive recall. It also reduces the number of physical actions necessary to input a value. Thus, providing default values is a kind of error prevention mechanism.

General principles

This can be applied to the design of an interactive system in order to promote its usability.

Standards

This can be apply specifically to either the hardware or the software used to build the interactive system

Visual information

This informs you of the incoming message then that will serve as a reminder that an unread message remains long after its initial receipt.

By authority

This is a dimension in classifying design rules which states that we mean an indication of whether or not the rule must be followed in design or whether it is only suggested.

Responsiveness

This is how the user perceives the rate of communication with the system. Also pertains to stability.

Multithreading

This is the ability of system to support user interaction for more than one task at a time

Observability

This is the ability of user to evaluate the internal state of the system from its perceivable representation.

Recoverability

This is the ability of user to take corrective action once an error has been recognized. Also pertains to reachability; forward/backward recovery; commensurate effort.

Task conformance

This is the degree to which system services support all of the user's tasks. This is also defined as task completeness and task adequacy.

Familiarity

This pertains to how prior knowledge applies to new system.

Reachability

This refers to the possibility of navigation through the observable system states.

Adaptability

This refers to the user's ability to adjust the form of input and output.

Guidelines

This states that a designer will have less of a need to know the underlying theory for applying a standard.

1. Strive for consistency 2. Enable frequent users to use shortcuts 3. Offer informative feedback 4. Design dialogs to yield closure 5. Offer error prevention and simple error handling 6. Permit easy reversal of actions 7. Support internal locus of control 8. Reduce short-term memory load

What are the Shneiderman's Eight Golden Rules of Interface Design?

Predictability Synthesizability Familiarity Generalizability Consistency

What are the principles affecting learnability?

Dialogue initiative Multithreading Task migratability Substitutivity Customizability

What are the principles of flexibility?

1) Nielsen's 10 Heuristics Shneiderman's 8 Golden Rules 2) Norman's 7 Principles

What are the two examples of the different collections in golden rules and heuristics?

1) Suggest how to increase usability 2)Differ in generality and authority

What are the two things to remember in using design rules?

Pre-emptive

What do you call the type of dialog system by which the system can initiate all dialog, in which case the user simply responds to requests for information.

Make things visible (Norman's Seven Principles for Transforming Difficult Tasks into Simple Ones)

Bridge the gulfs of execution and evaluation. The interface should make clear what the system can do and how this is achieved, and should enable the user to see clearly the effect of their actions on the system.

Familiarity

For a new user, the __________________________ of an interactive system measures the correlation between the user's existing knowledge and the knowledge required for effective interaction.

Standards and guidelines

It pertains to direction of design of the design rules.

Principles for usability

Repeatable design for usability relies on maximizing benefit of one good design by abstracting out the general properties which can direct purposeful design.

Level of abstraction

Rules also vary in their ________________________, with some abstracting away from the detail of the design solution and others being quite specific.

Affordances

Some psychologists argue that there are intrinsic properties, or _____________________, of any visual object that suggest to us how they can be manipulated.

Predictability

Support for the user to determine the effect of future actions based on past interaction history.

Generalizability

Support for the user to extend knowledge of specific interaction within and across applications to other similar situations.

Simplify the structure of tasks (Norman's Seven Principles for Transforming Difficult Tasks into Simple Ones)

Tasks need to be simple in order to avoid complex problem solving and excessive memory load.

Design patterns/ Patterns

The concept of a pattern language is generative and can therefore assist in the development of complete designs.

Learnability Flexibility Robustness

The principles to support usability are divided into three main categories which are?

Principles

These are abstract design rules, with high generality and low authority.

Principles

These are abstract guidelines applicable during early life cycle activities.

Design patterns/ Patterns

They are generally intuitive and readable and can therefore be used for communication between all stakeholders.

Principles

They can therefore be applied widely but are not so useful for specific design advice.

Visual communication

This can remain as an object which the user can subsequently manipulate.

Adaptability

This customization could be very limited, with the user only allowed to adjust the position of soft buttons on the screen or redefine command names.

Persistence

This deals with the duration of the effect of a communication act and the ability of the user to make use of that effect.

By generality

This is a dimension in classifying design rules which states that we mean whether the rule can be applied to many design situations or whether it is focused on a more limited application situation.

Substitutivity

This is allowing equivalent values of input and output to be substituted for each other. Also pertains to representation multiplicity and equal opportunity.

Adaptivity

This is automatic customization of the user interface by the system.

Dialogue initiative

This is freedom from system imposed constraints on input dialogue. It also states system vs. user pre-emptiveness.

Use both knowledge in the world and knowledge in the head (Norman's Seven Principles for Transforming Difficult Tasks into Simple Ones)

This states that people work better when the knowledge they need to do a task is available externally - either explicitly or through the constraints imposed by the environment. But experts also need to be able to internalize regular tasks to increase their efficiency. So systems should provide the necessary knowledge within the environment and their operation should be transparent to support the user in building an appropriate mental model of what is going on.

Design for error (Norman's Seven Principles for Transforming Difficult Tasks into Simple Ones)

To err is human, so anticipate the errors the user could make and design recovery into the system.

Get the mappings right (Norman's Seven Principles for Transforming Difficult Tasks into Simple Ones)

User intentions should map clearly onto system controls. User actions should map clearly onto system events. So it should be clear what does what and by how much. Controls, sliders and dials should reflect the task - so a small movement has a small effect and a large movement a large effect.

Rule's authority and generality

We can classify design rules along two dimensions. What are these two?

1. Use both knowledge in the world and knowledge in the head. 2. Simplify the structure of tasks. 3. Make things visible: bridge the gulfs of Execution and Evaluation. 4. Get the mappings right. 5. Exploit the power of constraints, both natural and artificial. 6. Design for error. 7. When all else fails, standardize.

What are Norman's Seven Principles for Transforming Difficult Tasks into Simple Ones?

Principles Standards Guidelines

What are the different types of design rules?

Browsability Defaults Reachability Persistence Operation visibility

What are the five other principles of robustness?

Concurrent multi-threading Interleaved multi-threading

What are the two types of multithreading?

Effective

_______________________ use of the affordances that exist for interface objects can enhance the familiarity of the interactive system.

General principles

What do you call the most abstract design rules?