The document discusses key concepts in human-computer interaction (HCI), including affordances, mapping, causality, constraints, and conventions. It explains the difference between perceived and real affordance, emphasizes the importance of mapping controls to their functions, and highlights various types of constraints necessary for effective application design. The conclusion reiterates that all steps in these processes are essential for successful application development.

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2. HCI
ASSIGNMENT
M U H A M M A D K A S H A N
U S M A N A H M A D
B A B A R A L I 2

3. OUTLINE
Affordance
Perceived Affordance
Real Affordance
Mapping
Causality
Constraints.
Conventions.
Conclusion
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4. AFFORDANCE
Affordance maens “What you can do with something”. (Neilsen/Budiu
)
An other definition of Affordance
“What the user CAN SEE that an OBJECT DOES”.
Affordance answers how do i use it?
• Giving a clue...!
• Example:
switch for toggling
chairs are for sitting
table for placing things on 4

5. TYPES OF AFFORDANCE
There are two types of affordance
 Perceived affordance.
 Real affordance.
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6. PERCEIVED AFFORDANCE
“The perceived properties of the object that suggest how one could use it”
OR
“Type of actions a user perceives to be possible”
Problems occur when
 These are not the same,
 People’s perceptions are not what the
designer expects
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7. PERCEIVED AFFORDANCE
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8. PERCEIVED AFFORDANCE
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9. REAL AFFORDANCE
• The actual actionable properties of the product
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10. REAL AFFORDANCE
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11. MAPPINGM
the relationship between control and their effect....
the natural relationship between controls and displays
e.g., when we preess the on button of swith then the light wiill be on...or off...
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12. MAPPING
Control-display compatibility
– cause and effect
steering wheel turn
left, car turns left
scroll bar – scroll
down
viewport goes down
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13. MAPPING PROBLEMS
Quick, open the top drawer
Mapping:
suggests it should open
the drawer but doesn’t
Affordance:
handle is for pulling
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14. CAUSALITY
the thing that happens right after an action is
assumed by people to be caused by that action
 interpretation of “feedback”
 false causality
• incorrect effect
– invoking unfamiliar function just as computer hangs
– causes “superstitious” behaviours
• invisible effect
– command with no apparent result often re-entered repeatedly
– e.g., mouse click to raise menu on unresponsive system
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15. CAUSALITY PROBLEMS
Effects visible only after Exec button is pressed
– Ok does nothing!
– awkward to find appropriate color level
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16. CONSTRAINTS
• The state of being checked, restricted, or compelled to avoid or perform some action.
• For the effective and efficient use of any application constraints are really necessary.
• There are certain types of constraints:
– Cultural constraints.
– Logical constraints.
– Physical constraints.
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17. CONSTRAINTS(LOGICAL)
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18. CONSTRAINTS(LOGICAL)
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19. CONSTRAINTS(LOGICAL)
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20. CONSTRAINTS(PHYSICAL)
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21. CONVENTIONS
• Conventions are actually cultural constraints.
• They can’t be change so easily.
• Designers must have to kept in mind and design according to the international
standards.
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22. CONVENTIONS(CALCULATOR)
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23. CONVENTIONS(FONT EFFECTS)
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24. CONVENTIONS(THE ATTACHMENT SYMBOL)
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25. CONCLUSION
• All steps are equally important.
• So all the steps must be considered while developing any application.
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26. THANK YOU !!!
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