2. Introduction
• Human
activites and task involve some form of
communication, in which information is exchanced between
one and more partisipants.
• People communicate with each other by talking, writing and
various forms of non-verbal communication.
3. Man-Machine
• People’s interactions with machines, tools, computers, consumer
products, and other devices they use to perform tasks can also be
viewed as a form of communication
• People tell machines or other devices what to do, using controls and
input devices, and are told what to do and what not to do by displays,
signs, signals, and other information-bearing cues in their
environment.
4. A communication system, as originally proposed b
Shannon (1948), consists of :
1.An information source that produces the message(s) to
be communicated
2.A transmitter that converts or codes the message into a
signal suitable for transmission
3.A channel that transmits the signal from transmitter to
receiver
4.A noise source that adds noise to channel
5.A receiver that reconstructs or decodes the message
from the signal
5. An Abstract Communication System
Source
of
Signal
Encoder &
Signal
Channel
Decoder &
Receiver
Destination
of Signal
Internal
noise
External
Noise
These components of a communication system are generic in nature and
can be used to distinguish a wide variety of communication scenarios (Lehto
& Miller, 1986)
6. Information Transmition
• The succesfully communicate a message, the message must first be
sent.
• For example, a speedometer might display the current speed of
vehicle. The intended receiver must then notice, understand and
respon appropriately after receiving the message.
7. KLM Flight 4805, Boeing 747-206B, PH-BUF, ground
collision with Pan American Flight 1736, Boeing 747121, N735PA
• Location: Tenerife, Canary Islands (Spain)
• Date: March 27, 1977
•
Both aircraft - KLM Flight 4805, a Boeing 747206B, Reg. No. PH-BUF; and Pan American
(Pan Am) Flight 1736, a Boeing 747-121, Reg.
No. N736PA, - had been diverted to Los Rodeos
Airport on the Spanish island of Tenerife in the
Canary Islands due to a bombing at the airport at
their final destination, the neighboring island of
Gran Canaria.
• Later, when flights to Gran Canaria resumed, the
aircraft collided on the runway in Tenerife as the
KLM Boeing 747 initiated a takeoff while the Pan
Am aircraft was using the runway to taxi.
8. • The Spanish investigative authority, Subsecretaria de Aviacion Civil,
found that the fundamental cause of the accident was the KLM captain:
1. Took off without clearance;
2. Did not obey the "stand by for take off" direction from the tower;
3. Did not interrupt take off on learning that the Pan Am aircraft was still on the
runway; and
4. In reply to the KLM flight engineer's query as to whether the Pan Am aircraft had
already left the runway, the KLM captain replied emphatically in the affirmative.
• The investigation also believed that the KLM captain's decision to take off
may have been influenced by revised crew duty time limitations recently
enacted by the Dutch government. The restrictions were inflexible and
highly penalizing to the captain, if exceeded.
• With a total of 583 fatalities, the crash remains the deadliest accident in
aviation history. All 248 passengers and crew aboard the KLM flight were
killed. There were also 335 fatalities and 61 survivors on the Pan Am
flight.
13. How to Calculate Information (coin
toss)
H = Log2n
50%
H : Amount of Information (bit)
n : The number of equally likely alternatives
H = Log2 2 = 1 bit
H = ∑pi * Log2(1/pi)
50%
n=2
90%
10%
Pi : Probability of ith event
i : Alternatives from 1 to n
H = 0,9*Log2(1/0,9) + 0,1*Log2(1/0,1) = 0,9*0,152 + 0,1*3,32 = 0,469 bit
15. Human Capability
• Vary among Human
• Sensory storage of ear :
10.000 bits/sec (not including
decision making process)
• Maximum information
processing vary 6 – 50
bits/second
• (Freivalds, 2009)
18. • Selective Attention
• A general finding of early reseach on human information
processing was that people are limited in their ability to
transmit information.
• People have a tendency to see or hear what they expect
to see or hear
19. • The Role of Working Memory
• When people perform tasks, they are constantly shuffling
information in and out of consciousness
• This process is nicely described by production system model of
human cognition (Newel & Simon, 1972; Anderson, 1983)
1.
Task performance is described in terms of the changing
contents of working memory in which has a limited capacity
of 5 to 9 items
2.
The content of working memory changes over time when
new information entering working memory replaces or over
writes the existing contents
3.
The new information can enter working memory when
information from the environment is perceived or when fact
are retrieved from long-term memory
20. Well integrated sources of information can act as cues that
trigger the retrieval of additional, and hopefully relevant,
information from long term memory
Providing information only at the time it is relevant also
reduces the chance of overloading working memory and
minimizes the change of distracting the operator
21. Example :
• Lockout tag is placed next to an activated lockout
• Switched are labeled on control panel
• Sign placed on a door warns against entering
22. • The Mode of Processing
• There are two modes of cognitive processing
1. One is outomatic, less capacity-limited, Possibly
parallel, Invoked directly by stimulus input
2.
The second requires conscious control, has severe
capacity limitations, is possibly serial and is invoked
in response to internal goals
23. • Decision Making
• The ultimate objective of the communication process is to
improve decision making of real people in real
environments
24. DISPLAY DESIGN
• Displays are devices designed to communicate messages
to people/machine/tools
Classical view of the human-machine interface (Chapanis, 1965)
25. • In most cases, display perform a supportive role, in which
they supplement other sources of information that might
be available to the person using the particular device
26. Types of display
• Visual display ; are the most encountered
• Static display (ex : sign, label, book)
• Dinamic display (ex : speedometer, fuel gauges, oil pressure, temperatur
indicator)
• Analogue & Digital display
• Warning or alerting display
• Predictive or historical display
• Instructional, command or advisory display
• Spatial display (diagram, figuren & chart)
• Symbolic display
• Pictorial display (images)
• Auditory display; tend to used for alerting or warning related
purposes (Wide array of sirens, horns, bells, tones, beeps or
buzzers)
27. Principle of Display Design (1)
• Sensory Modality
1. The most appropriate sensory modality of a display depends on its
intended function, sensory demands of the background of the
background task, and sensory capabilities of its intended audience
2. Display that combine sensory modalities can be particulary effective
when tasks are performed under changing condition
•
Display Location & Layout
1.
Locate visual displays where they can be seen and put more important
visual in more central locations
Display should provide their information at the time it needs to be used
Displays and display elements should be grouped consistently with the
sequence in which they are used by the operators
Tasks requiring information integration are better served by more
integrated object-like displays
2.
3.
4.
28. Principle of Display Design (2)
1. Object that are placed close together will be more likely to be viewed as being related
2. Position displays or display elements so they have obvious spatial referents
Legibility of Display Element
1. The minimum size of a critical detail should be 5 minutes of visual arc for novice
observers and not less than 2 minutes of visual arc for experienced operators
2. Symbols and alphanumeric characters should subtend a visual angle of at least 12
minutes of arc
3. Display should provide an adequate contrast between visual elements and their
background
4. Avoid crowding of display elements
5. Take steps to deal with the effect of degraded legibility due to aging and adverse
environmental conditions
29. For rapid and accurate identification of
individual characters, 16 to 18 minutes of arc
is normally adequate, although reading
speed continues to increase until character
height exceeds 22 arc minutes (Chung et al.,
1998; Giddings, 1972; Legge et al.,
1985; Legge et al., 1987; Legge et al., 1990;
Strasburger et al., 1991).
A width-to-height ratio (“Width”/“Height” in
Figure 7-4) shall be from 0.5 to 1 to 1
to 1 and, for optimal legibility and readability,
should be from 0.6 to 1 to 0.9 to 1.
Legibility is sometimes sacrificed to some
extent for esthetics, conservation of space,
or other practical considerations (Benson, L.,
& Farrell, 1988; Soar, 1955).
30. Principle of Display Design (3)
• Information Content and Coding
1.
Display instructions should whenever possible be stated in a positive manner
2.
Be Selective
3.
Let the user control the amount and detail of information presented
4.
Information about the current or desired state or condition of system, item,
5.
Display that mae derivative information easily available make it easier for people to
predict what will happen
6.
Be as realistic as possible in describing the variable you are trying to communicate
7.
The direction of movement of an indicator on a display should be compatible
8.
Color coding is a good tool for conveying relationship between display elements;
9.
Many coding schemes other than color, including shape
10.
Verbal and numerical codes tend tobe better understood and requires less learning than
symbols or other coding methods
11.
The use of analogies and metaphors often can greatly improve the learnability and
understandability of display element
12.
In most cases, line graph are preferred slightly over vertical bar graphs and preferred
strongly over horizotal bar graphs
13.
Multiple single line on single line are prefered over multiple single line graphs in point
reading
14.
Varioation in pitch, amplitude, an modulation can be used to specified distinguished
sounds.
31. • Presentasi
• ANSI-HFES 100, 2007
• Kelompok 1 : bab 5
• Kelompok 2 : bab 6
• Kelompok 3 : bab 7
• Kelompok 4 : bab 8
• Kelompok 5 : bab 1,2,3,4
