A) Technology usability Flashcards
How does Shackel define usability?
‘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)
Who developed the leaf criteria and what are the words for each letter?
- Shackel (1986/91)
- Learnability
- Effectiveness
- Attitude
- Flexibility
Learnability meaning in Shackel’s LEAF criteria
users must be able to learn to use the system after a certain amount of training
Effectiveness meaning in Shackel’s LEAF criteria
Use of system in a number of environments, within a certain time, and within error limits
Attitude meaning in Shackel’s LEAF criteria
positive attitude towards using the system and levels of tiredness or discomfort are kept to a minimum
Flexibility meaning in Shackel’s LEAF criteria
user performance must not degrade beyond a certain limit across tasks and environments
What did Nelson (1993) say about acceptability?
He accepted others focus on learnability, efficacy, ease of use and subjective considerations.. but considered acceptability as key.
What framework did Nielsen (1993) make
1993 Framework for usability.
Usefullness/usability comes after practical acceptability.
What did Jordan (1998) do following Nielsen’s usability concepts?
He extended Nielsen’s usability concepts to include system potential and system reusability
What is system potential in Jordan’s (1998) elaboration on learnability (2 points)
- Achieving optimal performance
- The optimal level of effectiveness, efficiency and satisfaction that is possible (The upper limit of experienced user performance).
What is reusability in Jordan’s (1998) elaboration on learnability (2 points)
- 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).
Usability and emotions
Human factors for pleasure in product use: Applied ergonomics (Marazano, 1998)
- Emotions associated with products
- Product properties that influenced the level of pleasure/displeasure: Associated behaviour:
- Marazano , 1998
Ease of use meaning
something that significantly impacts our emotional reaction to a product is ‘ease of use’
The Five E’s - What makes technology useable? - Quesenbery (2004)
- 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
Main people and studies for describing usability:(3)
- shackel
- booth
- nielson
What did Booth say about usefulness
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
User-system interaction: Important user issues (6)
- cognitive and perceptual abilities
- personality differences
- cultural and environmental diversity
- users with disabilities
- senior citizens and children
- physical abilities/ physical workspace.
User-system interaction: Important user issues personality differences example
resilience/perseverance/openness
User-system interaction: Important user issues cultural and environmental diversity example
User end goals/importance/permissions
User-system interaction: Important user issues cognitive and perceptual abilities example
Memory/problem solving/motivation
User-system interaction: Important user issues users with disabilities example
physical/perceptual/cognitive
User-system interaction: Important user issues physical abilities/ physical workspace example
physical properties (is the person strong enough to carry)/location (how far to carry)
Determinants of usability (5)
- 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)
