WELCOME TO UNIT 6: DESIGN & USABILITY
Constraint
Limit the likely actions that can be performed on a system. There are two types of constraints and they are physical constraint and psychological constraint.
Physical Constraint
- Bound the range of potential actions by redirect physical motion in specific ways.
- There are 3 types of physical constraint:
i) Paths
ii) Axes
iii) Barriers
Psychological Constraint
- Bound the range of potential actions by leveraging the way people perceive and think about the world.
- There are 3 types of psychological constraint:
i) Symbols
ii) Conventions
iii) Mappings
Physical Constraint
- Bound the range of potential actions by redirect physical motion in specific ways.
- There are 3 types of physical constraint:
i) Paths
ii) Axes
iii) Barriers
Psychological Constraint
- Bound the range of potential actions by leveraging the way people perceive and think about the world.
- There are 3 types of psychological constraint:
i) Symbols
ii) Conventions
iii) Mappings
PHYSICAL CONSTRAINTS
A) PATH
Path is a type of physical constraints that limits the action of an applied force only to a linear or one path motion such as the scroll bar.
Example: The linear path to change the colour intensity and brightness of the desktop borders, start menu and taskbar.
Source:
Printscreen from desktop
Explanation:
A user is able to change the intensity of colour and brightness by adjusting them by using the linear path motion
Path is a type of physical constraints that limits the action of an applied force only to a linear or one path motion such as the scroll bar.
Example: The linear path to change the colour intensity and brightness of the desktop borders, start menu and taskbar.
Source:
Printscreen from desktop
Explanation:
A user is able to change the intensity of colour and brightness by adjusting them by using the linear path motion
B) AXES
Axes is a constraint that keeps applied force in a rotary motion which serves as a space-saving control surface for an infinite length of subject control such as the types of actions you wish to apply to a multi cooker; warm, heat or boil.
Example: The knob of a multicooker
Source: Own
Explanation:
The cooking process of the multicooker can be adjusted using the knob in a rotary manner.
Axes is a constraint that keeps applied force in a rotary motion which serves as a space-saving control surface for an infinite length of subject control such as the types of actions you wish to apply to a multi cooker; warm, heat or boil.
Example: The knob of a multicooker
Source: Own
Explanation:
The cooking process of the multicooker can be adjusted using the knob in a rotary manner.
C) BARRIERS
Barriers provide physical constraints by eliminating or slowing down a particular undesired behaviour.
Example: The red and white pattern of line
Source: This photo was taken at FSKPM
Explanation: This red and white line provides a barrier in which the are covered by this line are not allowed for any standing.
Barriers provide physical constraints by eliminating or slowing down a particular undesired behaviour.
Example: The red and white pattern of line
Source: This photo was taken at FSKPM
Explanation: This red and white line provides a barrier in which the are covered by this line are not allowed for any standing.
PSYCHOLOGICAL CONSTRAINTS
A) SYMBOLS
Symbols provide psychological constraints by displaying icons and signage that explain a particular setting or object by taking human’s knowledge and thoughts into consideration.
Example: The Female symbol
Source: This picture was taken at CAIS, UNIMAS.
Explanation:
The symbol of a person wearing a dress symbolizes a female. The location of this symbol outside on the toilet door indicates that the toilet is specifically for the usage of females only. It constraint the entry of males.
Symbols provide psychological constraints by displaying icons and signage that explain a particular setting or object by taking human’s knowledge and thoughts into consideration.
Example: The Female symbol
Source: This picture was taken at CAIS, UNIMAS.
Explanation:
The symbol of a person wearing a dress symbolizes a female. The location of this symbol outside on the toilet door indicates that the toilet is specifically for the usage of females only. It constraint the entry of males.
B) CONVENTIONS
Convention changes human behaviours by considering learned knowledge, traditions and expectations. Convention helps to make a design more usable and understandable.
Example: The on and off push button of a mouse
Source: This picture was taken from the bottom of a mouse
Explanation:
When the mouse is in an " off " mode, the colour is red whereas when the mouse is pushed to be " on ", the colour is green. Thus, it meets the normal convention.
Convention changes human behaviours by considering learned knowledge, traditions and expectations. Convention helps to make a design more usable and understandable.
Example: The on and off push button of a mouse
Source: This picture was taken from the bottom of a mouse
Explanation:
When the mouse is in an " off " mode, the colour is red whereas when the mouse is pushed to be " on ", the colour is green. Thus, it meets the normal convention.
C) MAPPINGS
Another type of psychological constraint is mapping. Mapping modifies human behaviour by creating a relationship between specific design and perception. Mapping will give a better visibility and implying possible actions that can be done to use a particular design.
Example: A remote control with the television
Source: Taken from a house in Penang.
Explanation:
The buttons on the remote control has a close relation to the television. It provide psychological constraint since each button can perform a specified function or control towards the television.
Another type of psychological constraint is mapping. Mapping modifies human behaviour by creating a relationship between specific design and perception. Mapping will give a better visibility and implying possible actions that can be done to use a particular design.
Example: A remote control with the television
Source: Taken from a house in Penang.
Explanation:
The buttons on the remote control has a close relation to the television. It provide psychological constraint since each button can perform a specified function or control towards the television.