A) Technology usability

Question 1

How does Shackel define usability?

Answer 1

‘the capability in human functional terms to be used easily and effectively by the specified range of users given specified training and user support, to fulfil the specified range of tasks, within the specified range of environmental scenario’ (Shackel, 1986; 1991; 2009)

Question 2

Who developed the leaf criteria and what are the words for each letter?

Answer 2

• Shackel (1986/91)
• Learnability
• Effectiveness
• Attitude
• Flexibility

Question 3

Learnability meaning in Shackel’s LEAF criteria

Answer 3

users must be able to learn to use the system after a certain amount of training

Question 4

Effectiveness meaning in Shackel’s LEAF criteria

Answer 4

Use of system in a number of environments, within a certain time, and within error limits

Question 5

Attitude meaning in Shackel’s LEAF criteria

Answer 5

positive attitude towards using the system and levels of tiredness or discomfort are kept to a minimum

Question 6

Flexibility meaning in Shackel’s LEAF criteria

Answer 6

user performance must not degrade beyond a certain limit across tasks and environments

Question 7

What did Nelson (1993) say about acceptability?

Answer 7

He accepted others focus on learnability, efficacy, ease of use and subjective considerations.. but considered acceptability as key.

Question 8

What framework did Nielsen (1993) make

Answer 8

1993 Framework for usability.
Usefullness/usability comes after practical acceptability.

Question 9

What did Jordan (1998) do following Nielsen’s usability concepts?

Answer 9

He extended Nielsen’s usability concepts to include system potential and system reusability

Question 10

What is system potential in Jordan’s (1998) elaboration on learnability (2 points)

Answer 10

• Achieving optimal performance
• The optimal level of effectiveness, efficiency and satisfaction that is possible (The upper limit of experienced user performance).

Question 11

What is reusability in Jordan’s (1998) elaboration on learnability (2 points)

Answer 11

• Level of performance after non use
• The effectiveness, efficiency and satisfaction with which the specified users can achieve specified tasks with a particular product after a comparatively long period away from these tasks. (decrement in performance).

Question 12

Usability and emotions
Human factors for pleasure in product use: Applied ergonomics (Marazano, 1998)

Answer 12

• Emotions associated with products
• Product properties that influenced the level of pleasure/displeasure: Associated behaviour:
• Marazano , 1998

Question 13

Ease of use meaning

Answer 13

something that significantly impacts our emotional reaction to a product is ‘ease of use’

Question 14

The Five E’s - What makes technology useable? - Quesenbery (2004)

Answer 14

• effectiveness is the completeness and accuracy with which users achieve specified goals
• efficiency can be described as the speed (with accuracy) in which users can complete the tasks for which they use the product
• engaging - how pleasant, satisfying or interesting the piece is
• error tolerance involves how well the product prevents errors and helps users recover from any errors that occur.
• ease of leaning concerns how well the product supports both initial orientation and deeper leaning

Question 15

Main people and studies for describing usability:(3)

Answer 15

• shackel
• booth
• nielson

Question 16

What did Booth say about usefulness

Answer 16

The concept of usefulness needs to be incorporated into the definition of usability.
- eg buying an Apple Watch, and finding the date and time are too small to be useful as a watch; doesn’t matter how many extra fancy features it has; you’re unlikely to wear it continuously

Question 17

User-system interaction: Important user issues (6)

Answer 17

• cognitive and perceptual abilities
• personality differences
• cultural and environmental diversity
• users with disabilities
• senior citizens and children
• physical abilities/ physical workspace.

Question 18

User-system interaction: Important user issues personality differences example

Answer 18

resilience/perseverance/openness

Question 19

User-system interaction: Important user issues cultural and environmental diversity example

Answer 19

User end goals/importance/permissions

Question 20

User-system interaction: Important user issues cognitive and perceptual abilities example

Answer 20

Memory/problem solving/motivation

Question 21

User-system interaction: Important user issues users with disabilities example

Answer 21

physical/perceptual/cognitive

Question 22

User-system interaction: Important user issues physical abilities/ physical workspace example

Answer 22

physical properties (is the person strong enough to carry)/location (how far to carry)

Question 23

Determinants of usability (5)

Answer 23

• learning, skill development, knowledge acquisition (eg learning or relearning the system)
• ways of problem solving and reasoning (eg fixing problems and working out how to do things)
• memory limitations (eg passwords and remembering how to use the system)
• language communication and comprehension (eg., understanding the instructions or error messages)
• attentional capacity limitations (eg, sustained attention and visual attention)