FIT2001 W7 - Prototyping and Usability

What is a prototype/mockup?

A representation used to explore and communicate the proposed system

What are the advantages of Prototyping?

• Improved communication to stakeholders

• Risk reduction

• Save time and money from late changes

• Greater user satisfaction

• Design and technical exploration

• Reference for developers

What are the disadvantages of Prototyping?

• Confused with finished system

• May not be suitable at full scale

• Wasted effort

• Learning effort

• Scope creep

What is the cycle of prototyping?

Prototype, Review, Refine, Repeat

What are the pros and cons of Low Fidelity?

• Early feedback

• Easy to change

• Limited realism

What are the pros and cons of High Fidelity?

• Resembles finished product

• Reference for developers

• Can be used for usability testing and training

• Confused with finished system

• Learning effort

What is the definition of Usability?

The extend to which specified users can achieve specified goals with effectiveness, efficiency and satisfaction in a specified context of use

What are the 3 key outcomes of usability?

• Effectiveness - the accuracy and completeness users can achieve their goals

• Efficiency - The resources expended to achieve goals

• Satisfaction - The comfort and acceptability of the system to users

What are the 5 Usability evaluation criteria?

• Learnability - Can first time users complete tasks?

• Efficiency - After learning, how fast can users complete tasks?

• Memorability - After a break, can users regain proficiency

• Errors - Frequency, severity and recoverability

• Satisfaction - Is it pleasant to use?

Why does Usability matter?

• Helps complete work more efficiently

• Users feel more in control

• Improves experience of using the system

• Can improve sales

• Can improve adoption of systems

• Competitive advantage in market

What is Formative evaluation of Usability?

Occurs during development. Users experience prototypes, identify problems and provide feedback. May involve HCI experts

What is a Summative evaluation of Usability?

Occurs after development. Measures the interface’s current usability, such as task times, completion rates and satisfaction

List the common Usability measures

• Time to learn

• Speed of performance

• Error rate

• Retention over time

• Subjective satisfaction

How much of the project budget should be allocated to Usability?

10%