Quality issues surrounding the ergonomics and accessibility of a interactive computerbased LO are closely related concepts. Ergonomics refers to how the people-machine interaction is designed and corresponds to a person's physical and cognitive needs in order to facilitate use, whereas accessibility of an LO refers to how these features can be adapted to different needs, either physical or cognitive.
Ergonomics of computer-based LO's
Generally, two types of ergonomics can be distinguished. We define them here as follows:
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Physical ergonomics deals with the human body's responses to physical and physiological stresses. Relevant topics include repetition, vibration, force and awkward/static posture as they relate to musculoskeletal disorders.
- Cognitive ergonomics concerns mental processes such as perception, attention, cognition, motor control, and memory storage and retrieval as they affect interactions among humans and other elements of a system. Relevant topics include mental workload, vigilance, decision making, skilled performance, human error, human-computer interaction, and training.
In terms of instruments to evaluate high quality, it refers to userfriendliness of the interface of the LO, responding to questions like:
- Is the dialogue simple?
- Does the interface speak the users' language?
- Does the interface minimize the users' memory load?
- Is the interface consistent?
- Is feedback visible?
- Are the exits clearly marked?
- Do shortcuts exist?
- Are the error messages explicit?
- Are there means to prevent the errors?
- Does an online help exist?
You will find more ideas and instruments on this subject in our Q4R Repository by entering "ergonomics" as a keyword.
You can also discuss this subject in the Best Practices Wiki.
Accessibility of a Learning Object
As put forth by Jutta Treviranus, editor of the ISO/IEC JTC1 SC36 N1141 (2005), the accessibility of an LO "focuses on the description of the characteristics of the resource that affect how it can be perceived, understood or interacted with by users including:
a) what sensory modalities are used in the resource,
b) ways in which the resource is adaptable (i.e. whether text can be transformed automatically),
c) which methods of input the resource accepts , and
d) what alternatives are available."
These guidelines gives a good grip on what a high quality LO must take into account in terms of accessibility.
In this project, we focus on accessibility as to how a specific LO can be accessed by as many people as possible regardless of their disabilities and to their right of access to entities, often through use of assistive devices such as screen-reading web browsers, audio version of text or vice versa, color scheme to grayscales, etc.
Types of Disabilities that should be taken into account
- Cognitive Learning
- Auditory
- Visual (including blind, low vision, and color blind)
- Motor/Physical
- Speech
Common Risk factors
The following list is so-called quasi-disabilities. A learning object should account for and support by attaching checklists, guides or error messages designed to avoid these. In doing so, accessibility is increased and quality in this respect attained.
- Slow Internet Connection
- Old Browser
- Missing Plugins
- No Speakers
- Small Display (pda, mobile phone)
- Eyes busy / Hands busy
- Noisy Environment
To get more information consult the following authorities:
You will also find other resources (instruments, guides, checklists, etc.) on this subject in our Q4R Repository by entering the keywork "accessibility".