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INF1520-summary a - Summary Human-Computer Interaction
Human-Computer Interaction (University of South Africa)
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, lOMoARcPSD|8112944
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INF120
Summary
Design of everyday things
Pg 2: Poorly designed objects – are hard and frustrating to use. They don’t
provide clues on how to use them. The mind is ‘configured’ to interpret clues!
[Example – with door – how to open, if there aren’t hinges or handles?]
This is the principle of VISIBILITY. NATURAL DESIGN. If you provide the hints
at how to use the object – its much easier to use.
VISIBILITY indicates the mapping between the intended operation, and the
actual outcome. (pg 8)
Principle of MAPPING - show the user what happens with each control! THE
RELATIONSHIP BETWEEN THE CONTROL’S MOVEMENTS AND WHAT IT
DOES (for exmp – the car seat adjuster on the Merc – looks exactly like the seat
– so you can see exactly what it does)
(pg 7) Things for new device:
• Good instructions
• Visible operation (buttons etc)
• A visible (and immediate) outcome (feedback) – lights flashing, beep etc.
Pg 22 – Mapping must not be arbitrary, is must be sensible, natural, meaningful.
The less actions per button – the easier, because then it is more evident (visible)
what that control does.
The steering wheel – turn right, the cars goes right!
Natural mapping (pg 23) means to take physical analogies and cultural standards
– and use them, this will lead to immediate understanding.
AFFORDANCE – the PERCEIVED and ACTUAL properties of the object – how it
could easily be used. (A chair affords sitting). (pg 9)
Affordances provide hints as to how things are to be used – a ball for
bouncing/rolling, a plate for pushing, a slot for inserting etc… design has failed
when things need instructions!
In an article (end unit 3), Norman explains that there is also “perceived
affordance” – mainly when talking about screen-based interfaces. Because
nothing is really “real” there. Icons, cursors etc- are perceived. They are
1
Downloaded by Shaun Nyamanjerere ()
, lOMoARcPSD|8112944
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feedback for real affordances. Why perceived? Because a user can click
anywhere on the screen! (but only get feedback from clicking in certain places).
A real affordance would be physically locking the mouse buttons in places
where a user can’t click. The cursor changing shape (signaling to us that we can
actually click [with a result] – is a convention, or a cultural constraint – not an
affordance.
(11) CAUSALITY – seeing response to an action just taken. Poor design can
bring a lack of causality, or false causality. Leads to superstitions…
CONSTRAINTS – hints to limits the way an object can be used (pg 12)
PRINCIPLES OF GOOD DESIGN –
• Provide a good conceptual model
• Make things visible (both the use, and the feedback)
CONCEPTUAL MODEL – how your mind simulates the use of an object, and
allows you to work it without instructions etc. allows us to predict the effects of
our actions.
You don’t have to understand how it works – just the relationship between the
control and the outcome.
Norman says (article of end unit 3) it’s the most important piece in design –
the rest is just making sure the rest is consistent. If the model is not clearly
understood – affordances and constraints have little value.
Person – mental model
Object provides a system image (the visible part of the device)
Designer- design model
Pg16 Designer User’s
model mental
model
System
image
2
Downloaded by Shaun Nyamanjerere ()
INF1520-summary a - Summary Human-Computer Interaction
Human-Computer Interaction (University of South Africa)
StuDocu is not sponsored or endorsed by any college or university
Downloaded by Shaun Nyamanjerere ()
, lOMoARcPSD|8112944
http://wikistudent.ws
INF120
Summary
Design of everyday things
Pg 2: Poorly designed objects – are hard and frustrating to use. They don’t
provide clues on how to use them. The mind is ‘configured’ to interpret clues!
[Example – with door – how to open, if there aren’t hinges or handles?]
This is the principle of VISIBILITY. NATURAL DESIGN. If you provide the hints
at how to use the object – its much easier to use.
VISIBILITY indicates the mapping between the intended operation, and the
actual outcome. (pg 8)
Principle of MAPPING - show the user what happens with each control! THE
RELATIONSHIP BETWEEN THE CONTROL’S MOVEMENTS AND WHAT IT
DOES (for exmp – the car seat adjuster on the Merc – looks exactly like the seat
– so you can see exactly what it does)
(pg 7) Things for new device:
• Good instructions
• Visible operation (buttons etc)
• A visible (and immediate) outcome (feedback) – lights flashing, beep etc.
Pg 22 – Mapping must not be arbitrary, is must be sensible, natural, meaningful.
The less actions per button – the easier, because then it is more evident (visible)
what that control does.
The steering wheel – turn right, the cars goes right!
Natural mapping (pg 23) means to take physical analogies and cultural standards
– and use them, this will lead to immediate understanding.
AFFORDANCE – the PERCEIVED and ACTUAL properties of the object – how it
could easily be used. (A chair affords sitting). (pg 9)
Affordances provide hints as to how things are to be used – a ball for
bouncing/rolling, a plate for pushing, a slot for inserting etc… design has failed
when things need instructions!
In an article (end unit 3), Norman explains that there is also “perceived
affordance” – mainly when talking about screen-based interfaces. Because
nothing is really “real” there. Icons, cursors etc- are perceived. They are
1
Downloaded by Shaun Nyamanjerere ()
, lOMoARcPSD|8112944
http://wikistudent.ws
feedback for real affordances. Why perceived? Because a user can click
anywhere on the screen! (but only get feedback from clicking in certain places).
A real affordance would be physically locking the mouse buttons in places
where a user can’t click. The cursor changing shape (signaling to us that we can
actually click [with a result] – is a convention, or a cultural constraint – not an
affordance.
(11) CAUSALITY – seeing response to an action just taken. Poor design can
bring a lack of causality, or false causality. Leads to superstitions…
CONSTRAINTS – hints to limits the way an object can be used (pg 12)
PRINCIPLES OF GOOD DESIGN –
• Provide a good conceptual model
• Make things visible (both the use, and the feedback)
CONCEPTUAL MODEL – how your mind simulates the use of an object, and
allows you to work it without instructions etc. allows us to predict the effects of
our actions.
You don’t have to understand how it works – just the relationship between the
control and the outcome.
Norman says (article of end unit 3) it’s the most important piece in design –
the rest is just making sure the rest is consistent. If the model is not clearly
understood – affordances and constraints have little value.
Person – mental model
Object provides a system image (the visible part of the device)
Designer- design model
Pg16 Designer User’s
model mental
model
System
image
2
Downloaded by Shaun Nyamanjerere ()
