Shared Flashcard Set

Details

softeng 350
Human Computer Interaction
106
Computer Science
Undergraduate 3
06/02/2012

Additional Computer Science Flashcards

 


 

Cards

Term
What is Usability?
Definition
  • Usability is the measure of the quality of a user’s experience when interacting with a product or system

or:

  • Usability is a quality attribute that assesses how easy user interfaces are to use
Term
What are 6 Usability factors?
Definition
  1. Fit for use
  2. Ease of Learning
  3. Efficiency of use
  4. Memorability
  5. Error frequency and severity
  6. Subject satisfaction
Term
What does it mean to be fit for use?
Definition

System functions as expected

Term
What do we consider when looking at ease of learning?
Definition
  • Do you expect to have to read a manual or the help?
  • How much time are people prepared to invest in learning the system?
  • What are peoples usability expectations for the system?
Term
What do we cosider when looking at error frequency and severity?
Definition
  • How frequently do people make errors?
  • What is the cost of the errors?
Term
What is the difference between a slip and a mistake?
Definition

Slip:

  • User understands system and goal
  • Know what action they want to take
  • Performs incorrect action

Mistake:

  • May not even have the right goal
Term
How can we prevent slips?
Definition

Better interface design.

Term
How can we prevent mistakes?
Definition

Make the system easier to understand.

Term
Why should we aim to provide subject satisfaction?
Definition

If users like the interface:

 

  • They will make less errors.
  • They will persist longer when they are having problems.

Aesthetics! How nice it looks is incredibly important in this respect.

Term
What are 3 types of usability evaluation?
Definition
  1. Heuristic evaluation
  2. Performance measurement
  3. Usability studies
Term
What are heuristic evaluations performed?
Definition

Usability experts using a predetermined set of criteria designed to measure the usability of a proposed design.

 

evaluator follows a scenario through the design and tests each step against the heuristic criteria.

 

evaluator makes recommendations to the design team either through a written document or during a team meeting.

Term
What is the first law of usability?
Definition

Heuristic evaluation has only a 50% hit rate.

 

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Term
What are Neilsen's Heuristics?
Definition
  1. Visibility of System Status
  2. Match between System and the Real World
  3. User Control and Freedom
  4. Consistency and Standards
  5. Error Prevention
  6. Recognition Rather Than Recall
  7. Flexibility and Efficiency of Use
  8. Aesthetic and Minimalist Design
  9. Help Users to Recognise, Diagnose, and Recover from Errors
  10. Help and Documentation
Term
What is the Hick-Hyman law?
Definition

The time it takes for a person to make a decision as a result of the possible choices.

Term
What is Fitts' Law?
Definition

Time to target depends on size and distance.

Term
What is a usability study?
Definition

 

User test:

  • Get real users to try to perform specified tasks
  • Observe and record
  • Ask their opinion
  • Analyse results

 

Term
When should we use usability tests?
Definition

Early and often.

The earlier those problems are found and fixed, the less expensive the fixes are.

Term
When creating a usability test what should we do?
Definition

Plan EVERYTHING!

  • Use a template
  • Fill in everything, even parts that are ocmpletely obvious
Term
How should we design our tasks when creating a usability test?
Definition
  • Be specific!
  • Record completion paths
  • Step through tasks yourself
Term
Why should we use questionnaires?
Definition
  • Easiest way to gather satisfaction data
  • There are several standard questionnaires
Term
Should a usability test follow a script?
Definition

 

Yes! It should be scripted exactly.

  • Greeting
  • Ethics
  • Task instructions
  • Questionnaire

 

Term
In regards to a usability test, how is a pilot test performed?
Definition
  • Try the whole usability test out on one or two people
  • After pilot fix obvious problems
  • Repeat
Term
How can we ensure we maintain professionalism during a usability test?
Definition

 

Treat participants with respect

  • Assume they are not idiots, it is the software that is wrong

Treat developers with respect

  • They may have put their heart and soul into the product and worked overtime to get if finished for you to pull it apart

Make sure your report is

 

  • Fair and accurate
  • Tidy
  • Free from grammar and spelling errors

 

Term
What are the 4 basic parts of an action?
Definition
  1. Goal: we begin with some idea of what we want to happen; this is our goal.
  2. Execution: we must then execute an action in the world.
  3. World: to execute an action we must manipulate objects in the world.
  4. Evaluation: we must validate our action and compare the results with our goal
Term
What are the 7 stages of the Execution/Evaluation action cycle (EEC)?
Definition
  1. Goal
  2. Form intention \
  3. Specify action   |>Execution
  4. Execute Action /
  5. Perceive world state     \
  6. Interpret perception      |>Evaluation
  7. Evaluate Interpretation /
Term
Do goals specify particular actions?
Definition

 

  • No!

Goal > Intention > Actions > Execution

 

Term
How do we evaluate the results of our actions?
Definition
  • Perceive new state
  • Interpret what we perceive
  • Evaluate new state with goal
Term
At what point is the EEC initiated?
Definition

The EEC can be initiated at any point

 

Some goals are data-driven - initiated when an environmental event is perceived


Others are goal-driven - initiated when the person conceives of a new goal

Term
What is the Gulf of execution?
Definition

 

The gap between a user's goalfor action and the means to execute that goal.

 

Term
What is the gulf of evaluation?
Definition

The difficulty a user has in mapping the visuals and messages from the system back into his own mental model.

Term
What is a mental model?
Definition

cognitive representation of something that defines a logical and believable estimation as to how a thing is constructed or how it functions.

Term
What are the features of a mental model?
Definition
  • Unscientific
  • Partial
  • Unstable
  • Inconsistant
  • Personal
Term
Why are mental models usefull?
Definition

Designs that align with a user’s mental model will be easier for him or her to use.

Term
What is mapping?
Definition

The concept of mapping describes how we make connections between things

Term
Why should we use mappings?
Definition

Proper mapping can increase the usability of an interface.

 

Use natural mapping whenever possible.

Term
What is semantic distance?
Definition

The distance between what people want to do and the meaning of an interface element.

Term
What is Articulatory Distance?
Definition

The distance between the physical appearance of an interface element and what it actually means.

Term
What are Affordances?
Definition

A quality of an object, or an environment, which allows an individual to perform an action.


(Norman considers an affordance to be a relationship between an object and a user, not a property of an object)

Term
What is Affordance confusion?
Definition

When certain aspects of an object do not work in a way in which we assume they should.

Term
What are some fun facts about affordances?
Definition

 

  • What may be an affordance to one person may not be to another
  • The perception of affordance fosters usability
  • The affordances a user may need must be present
  • Affordances must not contradict the user’sexpectations

 

Term
When designing a use interface what should we focus on?
Definition
Reducing the gulf of execution and the gulf of evaluation.
Term
What tools are involved in concetual design?
Definition
  • Brainstorming
  • Card sort
  • Semantic networks
  • Personas
  • Scenarios
  • Flowcharts
  • Cognitive walkthroughs
  • Use cases
Term
What does conceptual design involve?
Definition
  • Structuring the information space
  • Creating alternative solutions
  • Determining which design concept to pursue
Term
What can card sorting be used for?
Definition

 

  • discover user-centered groupings
  • organize the information collected in the discovery phase
  • define groupings for menus, controls and Web page content
  • generate labels for menus, buttons and navigation links.

 

Term
What are some of the advantages of Card sort?
Definition
  • They are quick and easy to perform.
  • They can be done before any preliminary designs have been made.
  • They will let you know how people organize information.
  • They will expose underlying structures.
Term
What are some of the disadvantages of card sort?
Definition
  • They only involve the elements that you have written on the cards.
  • They suggest solutions that imply structures.
  • They become difficult to navigate with more categories.
Term
Waht is a semantic network?
Definition

A semantic network is a web of concepts that are linked through association.

Term
What are some of te advantages of semantic networks?
Definition
  • They allow an easy way to explore the problem space.
  • They provide a way to create clusters of related elements.
  • They provide a graphical view of the problem space.
  • They resonate with the ways in which people process information.
Term
What are the disadvantages of a semantic network?
Definition
  • They require knowledge of the problem space.
  • They can lead beyond the problem space.
  • There is no formal semantics for defining symbol meaning.
Term
What are Personas?
Definition

Personas are archetypes of actual users, defined by the user’s goals and attributes.

Term
How are personas created?
Definition

A persona is created by identifying the primary stakeholders and creating an identity based on the stakeholder profiles and other collection activities such as interviews and surveys.

Term
What should personas include?
Definition
  • A name
  • Goals and motivating forces
  • Behaviours and a personality
Term
What are the advantages of personas?
Definition
  • They are quick and easy to create.
  • They provide a consistent model for all team members.
  • They are easy to use with other design methods.
  • They make the user real in the mind of the designer.
Term
What are the disadvantages of personas?
Definition
  • They can be difficult to create if the target audience is international.
  • Having too many personas will make the work difficult.
  • There is a risk of incorporating unsupported designer assumption.
Term
What is a scenario?
Definition
A description of a typical task.
Term
What does a scenario describe?
Definition
  • The basic goal
  • The conditions that exist at the beginning of the task
  • The activities in which the persona will engage
  • The outcomes of those activities
Term
What are flowcharts?
Definition
  • Simple network diagrams that identify the pages of a Web site and the navigational links between them

Or even

  • Sophisticated diagrams that capture conditional junctures and computational processes
Term
What is a cognitive walkthrough?
Definition

The evaluator takes the part of the primary stakeholder and tries to accomplish that stakeholder’s various tasks

Term
What does physical design involve?
Definition
  • What it will look like
  • What components it will require
  • How the screens will be laid out
Term
What tools are used at the physical design phase?
Definition
  • Low-fidelity prototypes
  • Evaluations
  • Wireframes
  • Functional prototypes
Term
What are the two types of low fidelity prototypes Neilsen distinguished between?
Definition
  • Horizontal
  • Vertical
Term
What is the difference between a vertical prototype and a horizontal one?
Definition
  • A horizontal prototype covers the breadth of functionality
  • A vertical prototype covers the depth of functionality
Term
What are the 3 main criteria for low fidelity prototypes?
Definition
  • Easy an inexpensive to make
  • Flexible enough to be constantly changes and rearranged
  • Complete enough to yield useful feedback about specific design options
Term
What are the advantages of paper prototypes?
Definition
  • People are more comfortable criticizing paper prototypes
  • They can be used early and often.
  • They are inexpensive and easy to create.
  • They make design ideas visual.
  • No special knowledge is required; all team members can create them.
Term
What are the disadvantages of paper prototypes?
Definition
  • They are not interactive.
  • They cannot be used to calculate response timings.
  • They do not deal with interface issues such as color or font size
Term
When should we begin evaluting our design?
Definition
early in the design process.
Term
What does the MacLeamy curve show?
Definition

Design Effort/Effect vs. Time

  • ability to impact cost and functional capabilities
  • cost of design changes
  • traditional design process
  • Integrated Project Delivery Process

IPD basically has its bump earlier

Term
What was Neilsens advice for usability evaluations?
Definition
  • Use multiple independent evaluators
  • Use observer to record evaluator
  • Go through interface several times
  • Compare interaction against list of heuristics
  • Use heuristics specific to design
  • List heuristic problems and how the heuristic is violated
Term
What are Shneiderman's 8 golden rules?
Definition
  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
Term
What are Norman's 7 principles?
Definition
  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.
Term
What do wireframes define?
Definition
  • Basic page layout
  • Screen components
Term
How are wireframes developed?
Definition
  • from flowcharts and paper prototypes
  • basically more evolved paper prototypes that include detailed information about the interface elements
Term
What can wireframes be used for?
Definition

to create template layouts that can be used to impose a consistent structure throughout the interface.

Term
In regards to wireframes, how should webpages be designed?
Definition
  • Use layouts that are common to the domain
  • Use flexible design for Web pages
Term
How does working in a standardized enviroment help us?
Definition

Increases efficiency and promotes learning

Term
What are functional prototypes?
Definition
  • interactive prototypes that represent various degrees of functionality.
  • can either be horizontal or vertical
Term
In regards to Interface design, what are the benefits of high-level software tools?
Definition
  • User interface independance
  • Methodology and Notation
  • Rapid prototyping
  • Software support
Term
How do high-level software tools provide user interface independence?
Definition
  • They separate interface design from internals.
  • They enable multiple user interface strategies.
  • They enable multiple-platform support.
  • They establish the role of the user interface architect.
  • They enforce standards
Term
How do high-level software tools provide the benefit of Methodoloy and Notation?
Definition
  • They facilitate the development of design procedures.
  • They help in finding ways to talk about design.
  • They create project management.
Term
How do high-level software tools provide the benefit of rapid prototyping?
Definition
  • They make it possible to try out ideas very early.
  • They make it possible to test, revise, test, revise, . . .
  • They engage end users—managers and customers
Term
How do high-level software tools provide the benefit of
software support
?
Definition
  • They increase productivity.
  • They offer constraint and consistency checks.
  • They facilitate team approaches.
  • They ease maintenance.
Term
What do design principles do?
Definition
  • Guide interaction designers and help them make decisions that are based on established criteria
  • They do not prescribe specific outcomes; they function within the context of a particular design project.
Term
What can design principles be used for?
Definition
To determine if there are gulfs of execution or evaluation.
Term
What design principles does the gulf of execution relate to?
Definition
effectiveness principles.
Term
What design principles does the gulf of evaluationrelate to?
Definition

Efficiency principles.

Term
How does functionality become usefullness/effectiveness?
Definition
  • Presentation filter
  • Comprehensibility Barrier
  • Efficiency/usability
  • Learnability barrier
Term
What are the components of a framework for design principles?
Definition

 

Usability Goals

 

  • There are two main usability goals in the framework; comprehensibility and learnability.

Design Principle Categories

 

  • The framework also divides the design principles into twomain groups; efficiency principles and effectiveness principles.

Format to Describe Design Principles

 

  • The framework uses the format “serves the principle of … which promotes …” to describe the different principles.
  • Familiarity serves the principle of memorability, whichpromotes usability.

 

Term
In regards to usablity testing, what are the functionality requirements?
Definition
The system must have adequate functionality for a
particular task.
Term
In regards to usablity testing, what is the presentation filter?
Definition
The functionality must be made accessible through the presentation filter (interface).
Term
In regards to usablity testing, how do we overcome the comprehensibility barrier?
Definition

If the presentation is comprehensible, the comprehensibility barrier will be superseded.

 

This depends on the degree of efficiency/usability in the interface design.

Term
In regards to usability testing, how do we overcome the learnability barrier?
Definition
If the interface is comprehensible it will be learnable, there is a direct relationship.
Term
 In regards to usability testing, how do we gain effectiveness/usefullness?
Definition

If the user can learn the interface s/he can take advantage of the functionality and the interface will, therefore, be useful.

Term
Why is comprehensibility important?
Definition
  • An interface design that is easy to comprehend will be efficient and effective.
  • If a user does not understand the interface it will be useless.
Term
How is Comprehensibility achieved?
Definition
it highly dependent on the way in which the interface communicates its functionality to the user.
Term
How is learnibility achieved?
Definition

it is is based on comprehensibility: if you can’t understand it, you can’t learn it.

 

An interface with high usability will be easier to learn

Term
What is the relationship between Comprehensibility and Learnabilty?
Definition

recursive: we start with comprehensibility which affects learnability, which will in turn increase comprehensibility

Term
What makes something effective/useful?
Definition
Utility
Safety
Flexibility
Stability
Term
What makes something efficient/usable?
Definition
Simplicity
Memorability
Predictability
Visibility
Term
What is effectiveness?
Definition
the usefulness of a design.
Term
What is the effectiveness goal?
Definition
a design must fulfill the user’s needs by affording the required functionality.
Term
In terms of design principles, what is utility?
Definition
what the user can do with the system.
Term
In regards to design principles, why is safety important to effectiveness?
Definition
If a design has a high degree of safety, it will prove more useful than a design that involves a high degree of risk.
Term
How can recovery be implemented in interaction designs?
Definition
By incorporating appropriate undo functionality and robust
error recovery routines.
Term
In regard to design principles, what is the advantage of flexible tools?
Definition
Can be used in multiple environments and may address diverse needs.
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