Affordances and Usability Principles Flashcards
(30 cards)
What is essential to the transparency of actions afforded by a product, regardless of whether you are dealing with a tangible or graphical user interface?
The principle of visibility
What are affordances?
The potential uses we might have for an object, device, or element.
Why do we rely even more on visual information when attempting to determine affordances when dealing with graphical user interfaces?
Because we can’t physically interact with objects in this environment to investigate their actionable properties.
For example, in the physical world we can pick up a ball to judge how heavy it is or how hard it is, which can help us determine what we can do with the object. However, a ball within a computer game provides us with no such information.
What are natural signals?
The unconscious use of visual information to determine the affordances of things in the real-world.
For example, supported, flat surfaces provide the natural signal that objects can be placed or rested, whilst objects stacked on top of another provide the natural signal that objects at the bottom cannot be removed without destabilising the whole stack.
Do natural signals exist in human-computer interaction?
No; instead all signals are constructed or contrived.
How did we develop the ability to unconsciously use signals from the virtual world over time?
Primarily thanks to convention and consistency in design.
What is visibility in human-computer interaction?
Visibility is not just the presence of affordances, but the ease with which the user is able to locate them when they are arranged together.
What can happen if users can’t identify the informative/meaningful parts of the display immediately?
They are unlikely to establish what they can do and how they must interact in order to carry out their planned activities.
How would you provide natural signals to users?
Follow convention and use consistency to include familiar elements
What is the principle of findability?
Refers to the speed with which users are able to locate information, functions or affordances.
How do users identify the affordances in graphical user interfaces?
They rely on the cues provided by the designer.
In order to improve the findability of affordances in graphical user interfaces, what did designers do?
They developed a battery of standardised practices, methods and graphical representations.
These conventions or cultural constraints are central to most user experiences, and disregarding them is likely to impact the speed with which users are able to find whatever they are looking for within the display.
What is findability dependent on?
Consistent sets of cues
What are physical constraints?
When physical properties of objects’ constrain the affordances we perceive are available.
Physical contraints are a good thing; they limit the number of actions we perceive, saving our time, which is especially important when the object is meant to have only a few or just one possible action.
What are epistemic actions?
The process of trail-and-error
What are examples of physical contraints?
Size, Shape, Weight, and material
What are semantic constraints?
The meaning of a situation imposes limitations on the possible actions.
Example of semantic constraints: certain objects are associated with use in different parts of the house and outside (e.g. knives in the kitchen, trowels in the garden, and towels in the bathroom).
What are Cultural constraints
From the moment we are born every one of us is saturated with sensory input that is specific to who and what surrounds us.
Tangible objects have _____ constraints, but graphical objects present _____ constraints.
natural constraints, artificial constraints
What are the six constraints for graphical user interface design?
- Limiting the number of choices
- Constraining with text
- Cultural constraints
- Using constraints from the real-world
- Blocking certain options
- Preventing actions
What are the three main types of constraints?
Physical, semantic, and cultural
A sound to accomplany a “Download Complete” notification is an example of a…?
Cultural constraint
Why should you provide as few options to complete a task when designing a user interface?
Users will less likely to become confused
What is the difference between affordances and mapping?
Mapping is all the possible uses and action you can carry out with an object and affordances in the realtionship because the actions and their effects.
For example, a button affords pressing and this action causes an effect; this effect maps to the action.
To distinguish between mapping and affordances, we can think of the former as the quality or transparency of the relationship between the actions necessary to carry out a certain operation and the effect(s) of these actions. While affordances are the possible uses we might have for an object, which are determinable on the basis of the perceptible properties of the object.
