The document discusses important aspects of designing computer systems for people. It emphasizes understanding users through gaining knowledge of human characteristics, tasks, needs and psychological factors. Some key points discussed are: 1) Understanding how people interact with computers and their characteristics is essential for design. 2) Common usability issues like visual clutter, impaired readability, confusing navigation and distractions should be avoided. 3) Human perceptual abilities, memory components, vision and information processing affect design and must be considered.

2. DESIGNING FOR PEOPLE
THE SEVEN COMMANDMENTS
• Provide a multidisciplinary design team.
• Seek early and ongoing user involvement.
• Gain a complete understanding of users
and their tasks.
• Create the appropriate design.
• Perform rapid prototyping and testing.
• Modify and iterate the design as much as necessary.
• Integrate the design of all the system components.

3. 3.1 Introduction
The most important part of any computer system is
the understanding of the system user.
The following are the steps to be followed by
designer to create a truly usable system:
1. Understanding of how people are interacting with
computers.
2. Understanding of human characteristics importance
in the design.

4. 3.Identification of knowledge and experience at
users level.
How Do I Get Experience
When I Need Experience
To Get Experience?

5. 4.Identification of the characteristics of the users
needs, tasks and jobs.

6. 5. Identification of the Psychological characteristics of
the user.

7. 6. Identification of the Physical characteristics of the
user.
7. Employ the recommended methods for gaining
understanding of users.

8. Obstacles and Pitfalls in the Development
Path
Developing a computer system is
is not a simple task.
In general, we need to consider
many observations while
designing a system.
They are:
1) Nobody ever gets it right for the first time.
2) Its development is completely full of surprises.
3) Lot of changes are required to design a good
system.

9. 4) Ignoring change is not possible.
5)Though we designed a good system, people will
still make mistakes.
6) Designers require good tools for designing.
7) We must have behavioral design goals while
designing.

10. The damages which exists in designing a system are
called pitfalls.
They are:
1) No need for understanding and studying the users
needs.
2) Make concentration on design features or
components that are ‘neat’ or ‘with good quality’
etc.
3) No development of design element prototypes.

11. 4) No usability testing.
5) During user interface goals, there should be no
vision of common design team.
6) when there exists weak communication between
members of development team.

12. USABILITY
Some Definitions
 The capacity to be used by humans easily and
effectively, where:
Easily = to a specified level of subjective
assessment
Effectively = to a specified level of human
performance
 Learnability
 Efficiency
 Memorability

13. Common Usability Problems
Usability can be described as the capability to use an
application easily and effectively.
Common usability problems like ambiguous menus
and icons, inadequate error messages e.t.c decreases
the level of usability.
They are as follows:
1) Visual Clutter
2) Impaired information readability
3) Incomprehensible components
4) Annoying Distractions
5) Confusing Navigation

14. Visual Clutter
• Necessary things are covered by unnecessary,
meaningless graphics and wasteful decoration.
• Due to this visual noise users are wasting their time
for searching the necessary data.

15. Impaired information readability
Page readability is lessened/decreased by poor
developer choices in colors, graphics and type faces.
They diverts the user mind towards trying to know
about them instead of identifying and understanding
content. So, this diversion causes some delay in his
search.

16. Incomprehensible components
These components (Design elements) doesn’t
deliver the exact meaning of their functioning and
often leads user to be unobvious and confused about
them.

17. Annoying Distractions
The distractions mainly developed by the elements
those are constantly in motion,
Example:
• Blinking text, scrolling text.
• They destroy pages readability.
• Automatically presented sounds disturb users
concentration

18. Confusing Navigation
• Navigation links leads to dead-ends from which
there is no return or boomerang you right back to the
spot where you are standing with out you being
aware of it. Some navigation elements are invisible.
Confusing navigation violates users expectations.

19. 3.2 Human Interaction with Computers
Generally, business computer systems are designed
by the programmers, system analysts and system
designers.
Though they are good at programming and technical
knowledge, they don’t know how to increase
usability of the interface.

20. Due to the spread of internet and web throughout the
world, web got its own extensive graphical
capabilities.
Web evolved artistically as graphical artists are
being appointed who are good at both technical and
designing knowledge.
From there, the designs have been done by the
designer giving priorities to users capabilities.

21. • The interaction, specialized knowledge etc of
designers are leading the users to interpret and deal
with complex or confusing situations.
• Finally, their interfaces appear perfectly useful to
themselves rather than customers as they are unable
to understand the complexity.

22. The several factors that contribute to a poor
design are as follows.
Usage of specialized language.
Non-obvious design.
Fine dissimilarities.
Inconsistency in problem solving strategies.
Design inconsistency.

23. Usage of specialized language.
To operate a system, users often require to learn a
new terminology.
For a user this language appears completely strange
and complicated because of the presence of
unfamiliar words such as reboot, segment,
directories, URL’s (www.example.com), pathname
etc.
These words are used in
different context at homely
and official environments.

24. Non-obvious design.
Some designs are so complex such that they are not
obvious and one needs to learn them well.
Hence, outcomes are little late, nonobvious or
invisible too.

25. Fine dissimilarities.
Different actions may result the same work or
different works may result from the same action.

26. Inconsistency in problem solving strategies.
Problem-solving strategy is the most complex
activity which separates humans from other
information processing systems.
Problem solving is the process of finding a solution
to an unfamiliar task.

27. • Human use information to solve problems but hangs
up with difficulties as they do not follow
instructions properly before taking up an action.
• This is characterized as “trial and error” method.

28. • Human often get trapped in difficult situations
which makes the process of getting out of it
impossible while performing an operation to
accomplish the action.
• When such a situation arises human tends to turn off
the system and restarts it.

29. Design Inconsistency
Different information processing systems has similar
interface actions but are named differently on
different consoles, that is, the meaning of an action
to be performed renames the same but the pattern of
naming is different which makes its appearance
distinctive.
Examples:
i) “invalid” and “Not-Valid” both the commands
cause same thing to happen but are screened(shown)
differently on the monitor by naming them in a
different manner.

30. Psychological Responses to Poor Design
Errors are given much focus by the clients since they
affect their professional works efficiency.
Errors are considered as symptoms for
psychological problems because the magnitude of
errors is increasing day by day.
It led to various psychological and physical user
responses as follows:
Confusion
Irritation
Frustration
Panic or Stress
Boredom

31. Physical Responses to Poor Design
The physical responses affects the effectiveness of a
system thus resulting in failure of systems
capabilities and the prolonged actions and responses
that consumes considerable amount of time.
The following are the physical user responses that
would lead to poor design:
1) Rejection of a system.
2) Limited Usage of a system.
3)Indirect usage of a system.
4) Alterations in activity.
5)Wrong use of the system.

32. 3.3 Importance of Human Characteristics
The Human Characteristics that affects the design
are as follows:
• Human Perceptual abilities
• Components of memory
• Visual acuity
• Peripheral and foveal vision
• Sensory memory
• Information processing
• Learning process
• Skill acquisition
• Individual differentiation.

33. Human Perceptual abilities
Perception is nothing but understanding elements
and objects of an environment.
Perception refers to the human awareness about an
environment which can be experienced by means of
some physical sensation like vision, sound, smell
etc.
Awareness of an environment can be achieved by
classifying the stimuli based on the model stored in
memories.

34. 1) Proximity (or) closeness
If objects are close to one another then human
physical senses infer that the objects belong to each
other.

35. 2)Resemblance
If objects share similar visual properties such as
size, shape, color, brightness or orientation then
human physical senses realize that the objects
belong to each other.

36. 3) Compactness
A human eye when visualizes a simple or perfect
shape of an object, it becomes easy for them to
remember the object.

37. 4) Singularity
Objects are perceived as a group if they form closed
shapes.
5) Continuous
Extension of shortened lines are done automatically

38. Components of a memory
Memory consists of mainly two components:
1) Short-term
2) Long-term
A short term memory is also known as “working
Memory”.
A Long term memory provides information to
working memory.

39. Optimum Visual Acuity
The capacity of the eye to resolve details of any
object is called visual acuity.

40. Peripheral and foveal vision
A vision which is utilized to directly focus on
something is called foveal vision.
A vision which senses anything in its surroundings
is called peripheral vision.

41. Sensory Memory
Sensory memory acts as a buffer.
It automatically process information collected from
stimuli.
Sensory storage acts as a radar which frequently
scans the objects from the surrounding that are
important and passes it on to higher memory.

42. Information Processing
The information that is gathered by senses has
to be processed in an appropriate way:
There are two levels of information
Higher-level (capacity is limited, slow and
sequential)
Lower level(unlimited, processes quickly)

43. Learning process
Applying skills that allows one situation to be used
in another situation

44. Capability or Skill
The ultimate goal of human is to perform skillfully
which can be achieved by linking inputs and
responses into a sequence of actions.

45. Individual Differences
Individual differences complicates the design
process because human must be capable enough to
comfortably learn the task and this is possible if
design permits a wide variety of characteristics.