ISO 1503:2008

INTERNATIONAL ISO
STANDARD 1503
Second edition
2008-08-15
Spatial orientation and direction of
movement — Ergonomic requirements
Orientation spatiale et sens du mouvement — Exigences ergonomiques

Reference number
©
ISO 2008
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ii © ISO 2008 – All rights reserved

Contents Page
Foreword. iv
Introduction . v
1 Scope .1
2 Normative references .1
3 Terms and definitions .2
4 Design of spatial orientation and direction of movement .6
4.1 General.6
4.2 Ergonomic design of user interface (UI) with respect to orientation and direction .6
4.3 Steps in direction design .6
4.4 Design requirements/recommendations for human-machine interface (HMI) .7
4.5 Design recommendations for graphical user interfaces (GUI) .11
4.6 Design recommendations for combined control systems .17
5 Conformance.18
5.1 Applying requirements and recommendations .18
5.2 Evaluation of products.18
Annex A (informative) Constituent factors of usability.19
Annex B (normative) Reference model for spatial orientation and direction of movement.20
Annex C (informative) Flow of human-centred design activities .31
Annex D (informative) Spatial orientation and direction of movement design checklist .32
Bibliography .41

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 1503 was prepared by Technical Committee ISO/TC 159, Ergonomics, Subcommittee SC 4, Ergonomics
of human-system interaction.
This second edition cancels and replaces the first edition (ISO 1503:1977), which has been technically
revised.
iv © ISO 2008 – All rights reserved

Introduction
It is essential for the safety and usability of any system or product that the relationship between the direction
of its controls intended by a user/operator and the resulting direction of movement of the target object be
standardized.
For example, if the operation of fire-fighting equipment is not standardized, then swift and appropriate
operation in the event of a fire is difficult. If a one-hand lever is to be moved forward in Model A and backward
in Model B for speed-up of a railway electric car, frequent human error and, eventually, accidents are likely to
be caused. If a computer does not respond in accordance with what is shown on its screen, then its usability
and the efficiency of its user/operator will suffer. In construction work, effectiveness, efficiency and
user/operator satisfaction will be diminished if the user/operator's intention to make a dynamic change of the
target object is not well followed in the control of earth-moving machinery.
One of the purposes of this International Standard is to contribute to the enhancement of safety by preventing
human error during use as well as maintenance of a system and/or product. Another is to improve
effectiveness, efficiency and user/operator satisfaction by making the change of state and/or the movements
of a target object consistent with the user/operator's intention.
The first edition of ISO 1503 was constructed mainly in the framework of geometry regarding the definition of
three dimensional axes, geometrical orientation and the direction of control and display movements. This
revised edition incorporates the ergonomic issues that affect direction design with the aim of making the
standard more directly applicable in real-world situations. It deals with ergonomics design principles and
requirements for direction for products and work systems in a combined way — both for conventional
technical systems and newly developed information technology-related systems.
INTERNATIONAL STANDARD ISO 1503:2008(E)

Spatial orientation and direction of movement — Ergonomic
requirements
1 Scope
This International Standard sets out design principles, procedures, requirements and recommendations for the
spatial orientation and direction of movement of controls and displays used in tool machines, industrial robots,
office machines, earth-moving machinery, transportation (automobiles, railway electric cars/rolling stock,
aircraft, ships, etc.), information, daily commodities, public utilities and the operational components of building
facilities.
It lays down basic requirements for determining the operating direction of controls and the moving directions
or changing states of the target object, as well as other relations.
This International Standard
⎯ defines three dimensional axes, the observer, viewing systems, linear movement, rotary movement, two-
dimensional and three-dimensional movements in a dynamic space sequentially,
⎯ describes the four principles for determining the operating direction of a control, the moving direction of a
target object and/or display,
⎯ provides GUI (graphical user interface) design requirements and recommendations that integrate the
relationship between the computer operation and the movement of images on-screen in line with human
characteristics and to promote safety and efficiency in computer-assisted tasks,
⎯ sets out design principles and recommendations for determining the moving directions of a target object
and the controls of a combined control system using a multi-direction control that easily realizes the
complex operations intended by the user/operator as they are often seen in industrial apparatuses for
business use, and
⎯ gives principles and recommendations for the direction design of existing, as well as new, systems.
NOTE Ergonomics requirements or recommendations given in this International Standard can also be applied to
designing the direction of movement of other industrial goods, such as medical equipment, TV or PC game devices and
relevant machines/devices.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 6385:2004, Ergonomic principles in the design of work systems
ISO 9241-110, Ergonomics of human-system interaction — Part 110: Dialogue principles
ISO 9355-2:1999, Ergonomic requirements for the design of displays and control actuators — Part 2: Displays
ISO 9355-4, Ergonomic requirements for the design of displays and control actuators — Part 4: Location and
1)
arrangement of displays and control actuators
ISO 13407:1999, Human-centred design processes for interactive systems
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
axis
one of three assumed infinite mutually perpendicular straight lines through the centre point of the target object
NOTE The infinite straight lines run from behind to front, from left to right, and from top to bottom, corresponding to
the longitudinal axis, X, transverse axis, Y and normal axis, Z, respectively (based on the Cartesian system of
coordinates).
3.2
centre point
assumed reference point for the spatial orientation and determination of movements of a target object
NOTE The centre point is the primary standard provided by the intersecting point of three axes or three reference
planes. This point corresponds to the viewpoint of the observer (3.10) in the internal viewing system (3.20.2), and can
be located anywhere on the target object according to the purpose of observation in the external viewing system
(3.20.1). The centre point need not coincide with the gravitational centre of the target object.
3.3
mono-direction control
single-direction control
one or a set of controls that control the movements of a target object only on one axis at a time
3.4
multi-direction control
control unit that alone can control a target object in two or more moving directions along X, Y and Z axes and
in the planes composed of these axes or in the space composed of three planes
3.5
combined control system
control system in which two or more multi-direction controls (3.4) are applied
NOTE This system is seen typically in modern earth-moving machinery.
3.6
direction
position of a point in space relative to another point, independent of the distance between the two points

1) To be published.
2 © ISO 2008 – All rights reserved

3.7
human-centred design
user-centred design
design approach that is characterized by the active involvement of users, a clear understanding of user and
task requirements, an appropriate allocation of function between users and technology, iterations of design
solutions, and multi-disciplinary design
NOTE 1 See ISO 13407:1999, 5.1, for its principles.
NOTE 2 Usability engineering is often used as a substitute for human-centred design. But, applying usability
engineering methods does not necessarily prescribe the active user involvement that is the essence of human-centred
design. In addition, usability engineering often over-emphasizes the role of evaluation methods. Human-centred design,
on the other hand, refers to the process of analyzing context of use, eliciting user requirements, producing design
solutions and evaluating the design against the requirements — all in an iterative fashion.
3.8
clockwise, adv, adj
right-hand rotation
direction of a rotary movement of a target object to the right when viewed in direction X
3.9
anticlockwise GB, adv, adj
counter-clockwise US, adv, adj
left-hand rotation
direction opposite to clockwise (3.8) (right-hand) rotation
3.10
observer
real or hypothetical person who views a target object from outside or inside of it when determining the
direction or movement of a target object (3.14)
3.11
user
individual interacting with the system
[ISO 13407]
3.12
operator
person given the task of installing, operating, adjusting, maintaining, cleaning, repairing or transporting
machinery or a system
NOTE Within the context of this International Standard, the tasks performed concern the control of equipment or
devices.
3.13
reference plane
one of three perpendicular planes passing through the centre point of a target object (3.15) which, in each
case, contains two axes of the target object
NOTE The planes that contain longitudinal axis X and transverse axis Y, longitudinal axis X and normal axis Z, and
transverse axis Y and normal axis Z are called the basic plane, Pxy, longitudinal plane, Pxz, and transverse plane, Pyz,
respectively.
3.14
spatial orientation
direction-related inherent property of a target object (3.15)
NOTE Spatial orientation of a target object is characterized by pairs such as front-behind, right-left or up-down.
3.15
target object
object (including images) whose spatial orientation (3.14) or movements are to be defined, established or
controlled
3.16
usability
extent to which a product can be used by specified users to achieve specified goals with effectiveness,
efficiency and satisfaction in a specified context of use
[ISO 9241-11]
NOTE 1 See Annex A.
NOTE 2 For the purposes of this International Standard, user (3.11) is interchangeable with operator (3.12) for those
activities that involve movement of controls or target objects.
3.16.1
effectiveness
accuracy and completeness with which users achieve specified goals
[ISO 9241-11]
NOTE For the purposes of this International Standard, user (3.11) is interchangeable with operator (3.12) for those
activities that involve movement of controls or target objects.
EXAMPLE The percentage of attained goals.
3.16.2
efficiency
resources expended in relation to the accuracy and completeness with which users achieve goals
[ISO 9241-11]
NOTE For the purposes of this International Standard, user (3.11) is interchangeable with operator (3.12) for those
activities that involve movement of controls or target objects.
EXAMPLE The time needed to complete a task.
3.16.3
satisfaction
freedom from discomfort and positive attitudes towards the use of the product
[ISO 9241-11]
EXAMPLE The frequency of willingness to use.
3.16.4
context of use
users (3.11) or operators (3.12), tasks, equipment (hardware, software, and materials) and the physical and
social environments by, with or in which, a product is used
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3.17
user interface
UI
man-machine interface
MMI
human-machine interface
HMI
human-system interface
HSI
component of an interactive system (software or hardware) that provides the information and controls
necessary for the user to accomplish specific tasks with the interactive system
NOTE Adapted from ISO 9241-110.
3.18
viewing direction
assumed direction to which an observer (3.10) looks, when determining the direction (3.6) of a
target object (3.14)
3.18.1
viewing direction X(E)
viewing direction from the front side of a target object (3.15) toward the centre point (3.2) along the
longitudinal axis (3.1) in the external viewing system (3.19.1)
NOTE See Annex B.
3.18.2
viewing direction X(I)
viewing direction from the centre point (3.2) of a target object (3.15) toward the front side along the
longitudinal axis (3.1) in the internal viewing system (3.20.2)
NOTE See Annex B.
3.18.3
viewing direction Y
viewing direction along the transverse axis, Y, to the right
NOTE See Annex B.
3.18.4
viewing direction Z
viewing direction along the normal axis, Z, below
NOTE See Annex B.
3.19
viewing point
position of an observer's (3.10) eye
3.20
viewing system
system in which position, posture and viewing direction (3.18) of the observer (3.10) are fixed with
reference to the three axes of the target object (3.15) in order to render possible its spatial orientation
(3.13) and determination of its directions of movement
3.20.1
external viewing system
EVS
viewing system in which the location of the observer (3.10) is assumed to be outside the target object (3.15)
NOTE See Annex B.
3.20.2
internal viewing system
IVS
viewing system in which the location of the observer (3.10) is assumed to be inside the target object (3.15)
NOTE See Annex B.
4 Design of spatial orientation and direction of movement
4.1 General
This clause relates to direction design: basic ergonomics recommendations for user interfaces (4.2), the
ergonomics steps for direction design (4.3), individual ergonomics requirements and recommendations for
human-machine interfaces (4.4), and graphical user interface (4.5) and combined control (4.6) design
recommendations.
Detailed requirements for spatial orientation and direction of movements are given in Annex B.
4.2 Ergonomic design of user interface (UI) with respect to orientation and direction
The ergonomic design of a UI includes
⎯ anthropometric aspects (e.g. body size, hand reach envelopes, visual field),
⎯ cognitive aspects (e.g. compatibility of information displays/controls, human error tolerance),
⎯ physiological capability aspects in information processing (e.g. workload, information processing speed,
accuracy), and
⎯ environmental aspects (e.g. illumination, colour, noise).
UI design should be human-centred. Since the design of orientation and direction of movement of a target
object is a crucial component of UI design, the displays and controls and their relationship should be easy to
understand and use. The UI should be designed taking into account safety, usability and human
characteristics (sensing, sensitive intention, perception, human communication, etc.).
Human-centred design features the following essential conditions (see ISO 13407 and Annex C):
a) a clear understanding of the requirements/constraints of the user/operator and the task in question
through the user's/operator's active involvement;
b) an appropriate allocation of function between the user/operator and the machine for the accomplishment
of the task;
c) frequent review of the design based on feedback from the user/operator;
d) collaboration among team members throughout the process.
4.3 Steps in direction design
Major goals of direction design are to ensure safety, efficiency, ease of use and comfort. The designer's first
undertaking is to clarify the main goals of the direction design of the controls/displays within systems design.
Safety should be given a high priority, among multiple goals, in the design. Direction of movement design is
accomplished through specifying the task in question, determining the user(s)/operator(s) and determining the
relative priorities of safety, efficiency, ease of use and comfort.
Direction of movement design includes the following steps.
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a) Define the task and function.
b) Specify the user/operator in accordance with ISO 13407.
c) Specify the task in terms of
1) the movements/displays of the target object and controls to perform the task,
2) relative priorities in conducting the task (safety, efficiency, ease of use or comfort),
3) user's/operator's working posture in performing the task,
4) work space where the task is performed,
5) the flow of information for conducting the task, and
6) environmental factors (e.g. ambient illumination, necessity of protective clothes).
d) Define movements/displays of the target object and location of the controls.
1) Specify an area as a specific layered zone, corresponding to the view area and the frequency and
priority of the controls used within the area, in accordance with ISO 9355-2:1999, Figures 1 and 2.
2) Specify the location of the displays and controls, according to priority of function in the task, in
accordance with ISO 9355-2:1999, 4.1 and ISO 9355-4, 4.3.
3) Specify the arrangement of the displays and the controls in accordance with ISO 9355-4, 4.4.
4.4 Design requirements/recommendations for human-machine interface (HMI)
4.4.1 General
When designing an HMI, designers shall determine the operating directions of the controls and movements of
the target object considering ergonomic design principles in accordance with ISO 6385:2004, 3.6.5, while
taking into account the population stereotype. In case a stereotype does not exist, either the mental model or
metaphor may be taken into account.
NOTE “Population stereotype” is a natural human sense with respect to the directions of movement and operations
(see Reference [6]). For example, drivers expect that a car will turn right if they turn the steering wheel to the right, and
when learning how to drive they are trained to use the brake as a knee-jerk reaction — which is how stereotypes are
formed.
When arranging two or more displays units and controls, attention shall be paid to their directional
consistency. The following is also recommended.
a) Displays and controls should function in a manner to reduce the probability of human errors.
b) Displays should be selected, designed and laid out in a manner compatible with the characteristics of
human perception and the task to be performed.
c) Controls should be selected, designed and laid out in such a way as to be compatible with the
characteristics (particularly of movement) of that part of the body by which they are to be operated and
the task to be performed. Skill, accuracy, speed and strength and dexterity requirements should be taken
into account.
d) Controls should be selected and arranged, where possible, within the constraints of the space available to
suit the target population stereotype, sequence and movement of controls.
e) Controls should be selected and laid out in a manner compatible with the dynamics of the control process
and its spatial representation.
f) Controls should be close enough to facilitate correct operation where they are to be operated
simultaneously or in quick succession. However, they should not be so close as to create a risk of
inadvertent operation.
Figure 1 shows the framework of a direct boundary formed functionally and morphologically between the
user/operator and real-world target objects.

Figure 1 — Conceptual model of human-machine interface
4.4.2 Operating directions of controls
4.4.2.1 Coordination between operation and movement
When designing a display/control interface, the operating direction of controls shall be compatible with the
intended movement of the target object.
EXAMPLE 1 The linear movement of a target object to the right corresponds to pushing a lever to the right.
EXAMPLE 2 The clockwise rotary movement of a target object results from turning a hand-wheel clockwise.
However, in some cases, stereotypes of the user/operator population contradict this natural relationship and
different solutions may be required.
EXAMPLE 3 Movement of a small boat's tiller is opposite to the direction in which the boat turns in response.
4.4.2.2 Coordination between similar controls
In order to achieve the same or similar movements or changes among target objects, regardless of whether
the target objects are of similar or different types, controls of the same or similar types shall be operated in the
same direction.
4.4.2.3 Coordination with different controls
When technical reasons demand that different target objects undergo the same movement or change using
different controls, the movements of the controls and the resulting changes in the target objects shall be
compatible with the series of pair concepts given in Table 1 and consistent within each column, Group A or B.
8 © ISO 2008 – All rights reserved

Table 1 — Pairs of terms for the coordination between controls and the target object
Group A Group B
Left, port Right, starboard
Below Above
Down Up
Position
Bottom Top
Behind: EVS on side turned from observer Front EVS on side turned to observer
IVS in the stern; at end IVS in the bow; at the nose
End Beginning
To the left To the right
Downward Upward
Towards the user/operator Away from the user/operator
Direction of
Anticlockwise rotation Clockwise rotation
movement
Backward: EVS to user's/operator's  Forward: EVS opposite to user's/ operator's
viewing direction  viewing direction
IVS opposite to user/operator's IVS to user's/operator's viewing
viewing direction  direction
Dark Light
Cold Warm
Soft, quiet Loud
Slow Fast
Condition
Plus (+)
Minus (−)
Decelerate (brake) Accelerate
To increase effects (e.g. brightness, speed, power,
To reduce effects (e.g. brightness, speed, power,
pressure, temperature, voltage, current, pressure, temperature, voltage, current, frequency,
luminous intensity)
frequency, luminous intensity)
To switch off To switch on
To open an electric circuit To close an electric circuit
To put out of service To put into service
To stop To start, to go
To release To fasten, to engage
To close a valve To open a valve
Action
To extinguish To ignite
To empty To fill
To pull To push, to depress
To uninstall To install
To download To upload
To scroll down To scroll up
4.4.2.4 Change of controls
Even when the operating direction of the conventional controls is not compatible with the requirements of
4.4.2.2 and 4.4.2.3, designers shall not reverse the conventional operating direction in order to meet the
requirement; instead, the mode of the controls shall be changed to ensure the essential safety as follows.
a) If the clockwise rotation of the hand-wheel results in the anticlockwise movement of a machine part, the
anticlockwise rotation of the hand-wheel shall not subsequently cause an anticlockwise movement of the
machine part. The hand-wheel may be replaced by a lever or push buttons whose control movements
meet the requirements of 4.4.2.1 and 4.4.2.2.
b) If the lifting of a lever in a motor vehicle causes the left flashing indicator to light, lowering the lever shall
not cause the left indicator to light at any future point. However, the lever may be set at right angles or
replaced by push buttons or a rotating control element in order to meet the requirements of 4.4.2.1 and
4.4.2.2.
c) If a lever cannot be used, linear movement of the target object to the right shall be achieved by turning a
hand-wheel clockwise, or by operating the right-hand button of two corresponding push buttons.
4.4.2.5 Markings
The controls shall have markings, such as clear symbols or characters: symbols are preferable because they
are generally easier to understand.
4.4.3 Movement of target object and operating direction of controls
The relation between the target object movement and operating direction of controls shall be determined as
follows.
a) Direction of movement of linear controls (see ISO 9355-4):
⎯ switches and levers on a vertical panel are directed upward for ON/increase and downward for
OFF/decrease;
⎯ switches and levers on a lateral (horizontal) panel are directed forward (away from the user/operator)
for ON/increase and backward (toward the user/operator) for OFF/decrease.
b) Direction of rotary movement of controls:
⎯ controls are turned clockwise for ON/increase and anticlockwise for OFF/decrease.
NOTE Nevertheless, the stereotype can contradict this because of the mechanical design used for the control.
For example, flow control valves are typically rotated anticlockwise to increase the flow due to the fact that, when
rotated in the reverse direction, they screw in to shut off the flow.
4.4.4 Direction of target object movement and operating direction and location of controls
4.4.4.1 Target object moves in same direction as controls
When the target object moves linearly, the controls should move linearly.
When the target object rotates, the controls should rotate.
However, if stereotypes indicate a direction of movement contrary to the natural direction specified above,
consider tilting the control surface up or down to compensate.
EXAMPLE If a lever control moves backwards for moving the target object forwards, tilt the control surface down so
that the backwards movement of the control is toward the upward direction at the same time.
10 © ISO 2008 – All rights reserved

4.4.4.2 Target moves linearly and controls rotate
When the target object moves linearly and the controls rotate, the controls should be placed below or on the
right of an indicator, if any, showing the movement of the target object.
4.4.4.3 Target rotates and controls move linearly
When the target object rotates and the controls move linearly, unless the target object is hidden behind the
controls during operation, the controls should be placed below or on the right of any indicator, showing the
movement of the target object.
4.4.4.4 Biomechanical forces
When a user/operator is inside a moving target object, biomechanical forces can affect the recommended
location and direction of movement of controls. In such cases, biomechanical force effects should be
considered, which could result in a design that differs from that specified in this International Standard.
EXAMPLE In a railway operation, the dynamic acceleration effect on the operator's whole body induced by an
operational action might cause unintended effects on subsequent operations due to unnatural working posture.
4.4.5 Arrangement of two or more displays and controls
In cases when two or more displays or controls are arranged side by side and required to be positioned in a
certain sequence, they should be arranged as described in ISO 9355-4:—, 4.4.1.5. However, it is important to
consider the direction of movement of both displays and controls when arranging them, taking into
consideration their functional relationships.
4.5 Design recommendations for graphical user interfaces (GUI)
4.5.1 General
The following subclauses provide design recommendations related to direction-setting in a situation in which a
user/operator interacts with a target object in the virtual or real world via a GUI, which typically includes a
graphic display, pointing device and keyboard, employing information and communications technology (ICT).
It does not cover situations in which the user/operator directly (or sometimes remotely) interacts with a real-
world object mainly via physical manipulation devices.
4.5.2 Direct control interaction with virtual objects and indirect control interaction with real-world
objects
It needs to be noted that the distinction between a), b) and c), as follows, might not always be clear. For
example, the user/operator interacting with a driving simulator intended for driving practice could have a real-
world car as specified in type b) or even c) in mind, while a driving simulator intended for use in development
or testing can provide interaction as a virtual target object of type a). Electronic documents are generally
understood as being virtual objects that provide interaction of type a), but for user's/operators highly
experienced in environments in which high-precision display equipment and high-speed printers can be used,
they could be taken as type b) or even type c) interaction tools, through which it is possible to work with an
image of real-world paper documents in mind.
a) Direct interaction with a virtual target object
The user/operator directly interacts with, and controls, a virtual object implemented through ICT. Virtual
objects may include purely logical or abstract control objects that do not correspond to real-world target
objects. See Figure 2.
EXAMPLE 1 Viewing objects in a virtual museum using a virtual reality modelling language (VRML) viewer.
EXAMPLE 2 Searching/exploring/navigating in a huge information space (such as a large-scale website).
EXAMPLE 3 Operating a driving or flight simulator.
Figure 2 — Conceptual representation of direct control interaction with virtual target object
b) Indirect control interaction for real-world objects
The user/operator interacts with a displayed representation of a real-world target object via ICT. See
Figure 3.
EXAMPLE 1 The shutdown of a computer using a dialogue box on the display screen.
EXAMPLE 2 A web monitoring camera in which the viewing directions can be changed up, down, left or right using
software controls such as knobs and sliders of the form within the web page.

Figure 3 — Conceptual representation of indirect interaction with real-world target object
c) Direct interaction with real-world target object using information from virtual target object
The user/operator directly interacts with, and controls, a real-world target object using the information
from the virtual target object generated in a display space via ICT. See Figure 4.
EXAMPLE 1 Surgery performed by a surgeon looking at the display of a diseased organ via visualization
technology such as an endoscope or an ultrasonic computed tomography (CT).
EXAMPLE 2 Driving an automobile in reverse while looking at a rear-view camera or a monitor.

Figure 4 — Conceptual representation of direct interaction with a real-world target object using
information from virtual target object
12 © ISO 2008 – All rights reserved

4.5.3 Dialogue principles
For the application of dialogue principles in design, ISO 9241-110 shall be consulted.
4.5.4 Design of virtual target object
4.5.4.1 General
The following subclauses (4.5.4.2 to 4.5.4.10) give recommendations that are specific to orientation and
direction design where the user/operator engages in interaction with a virtual target object in a GUI type
environment. Most of these recommendations apply to the three interaction types described in 4.5.2, but
where a provision applies only to one of these types, it is so indicated.
4.5.4.2 Correlation of a virtual target object to a real-world target object
Mapping of real-world target objects into virtual target objects should directly correspond to the information
necessary to perform the task.
NOTE It is desirable that virtual objects be made to resemble, or to be analogous to, real-world objects, in aspects
such as their appearance and functions, from the perspective of making use of the user's/operator's experiences and
raising situation awareness.
NOTE Making a virtual target object similar or analogous to a familiar real-world target object is also important for the
same reasons, even for those cases where there is no corresponding real-world target object.
Where purely logical or virtual target objects lacking corresponding or comparable real-world target objects
are used, such as complex numbers and negative resistance, supporting means such as on-line help or
guided tours should be made available to help the user/operator manipulate such objects without difficulty.
4.5.4.3 Presentation of environmental information
Presentation of environmental or surrounding information should be compatible with the user's/operator's
recognition. Such information should be considered in the design of virtual object space to enhance the
user's/operator's situation awareness and to support his or her situation judgment and decision making.
4.5.4.4 Reduced dimensionality
The display space (display screen) through which the user/operator interacts with the virtual target object is
typically a two-dimensional space. When a real-world three-dimensional object space is presented in such a
two-dimensional space using some projection techniques, loss of some information is unavoidable. The
following is recommended in order to prevent or limit negative consequences of such loss of information.
a) The axis that has the smallest effects on the task performance should be used as the longitudinal axis in
the projected space.
b) If all three axes are of equal importance in performing the task, spatial correspondence to the real-world
control may be sacrificed and an abstract or idealized virtual space should be considered.
c) If insufficiency of depth perception arises (even if three-dimensional display technology is available),
countermeasures should be taken to cover such insufficiency.
4.5.4.5 Display capacity
The amount of information that can be presented by a display screen used as a virtual object space is
insufficient for expressing a real-world object space with sufficient fidelity. Relative to this, the following is
recommended in the design of a virtual object space.
a) Where the amount of information that has to be displayed is far greater than the display device capacity,
software techniques such as fine-coarse display, fish-eye display, bird's eye views and display scrolling
should be used — but only to the extent that they do not introduce unacceptably large distortions in the
display of the information, thus affecting the task performance.
b) Abstraction and idealization of information should be used to the extent that the real-world object space
information necessary to carrying out the task is preserved.
NOTE 1 A fine-coarse display is a technique which shows a specific area of concern, in a map for example, in detail,
sometimes making the periphery opaque
NOTE 2 A fish-eye display is, like a picture taken using a fish-eye lens, used to show a wide area around the
user/operator, with the focal area shown in detail and the periphery roughly.
NOTE 3 A bird's eye view is a three-dimensional scene, looked down on as if from altitude and covering a wide area.
4.5.4.6 Perceptual modality
Display devices used as virtual object space are usually limited to conveying visual and auditory information.
Olfactory and other perceptual information (surrounding information), including smells, vibration and tilting,
cannot be generally conveyed to the user/operator. Relative to this, the following is recommended in the
design of a virtual object space.
a) If sufficient display capacity is available, presentation of environmental information such as odour and
vibration, utilizing appropriate information visualization techniques, should be considered.
b) The use of haptic and tactile devices to convey surrounding information should be considered.
4.5.4.7 Frame of reference
When a virtual object space (display screen) is placed and viewed within the user's/operator's field of vision,
the display frame and its surrounding environment should serve as a frame of reference through which the
viewed object is recognized. The movement of an object or several objects in the display frame in one
direction can induce the perception of movement of the display frame or viewer in the opposite direction. Care
should be taken in the design of the virtual target object space such that the frame of reference does not
cause unintended effects of motion perception or motion sickness that adversely affect task performance for
which the object space is intended.
4.5.4.8 Manipulation of an object and viewing point
In accordance with the needs of the task, functions for manipulating the target object and/or functions for
manipulating the viewing point should be provided: the former corresponds to IVS (internal viewing system)
and the latter to EVS (external viewing system) in the case of real-world target objects. The means of
employing these functions should be easily distinguishable, especially where both functions are provided, in
which case the methods of employing similar functions (such as moving the target object forward and moving
the viewing point forward) should be consistent. Whether the target object or the viewing point is moved
forward, it should be distinguishable to the user/operator.
4.5.4.9 Direction of notation in logical or abstract quantities [4.5.2 type c) interface]
While this International Standard deals with spatial orientation and direction of movement, this subclause
provides recommendations for displaying direction of logical or abstract quantities within the relation to
direction of control. It is concerned with the direction of notation of additive quantities, sequential quantities,
hierarchy structures, time and relations between the directions of displays and controls. Descriptions of the
horizontal orientation are related to the orientation in which the language used is written. Only languages that
are written from left to right are considered.
14 © ISO 2008 – All rights reserved

a) Additive quantities
Additive quantities (e.g. mass, length, numbers of items and prices) are also referred to simply as
quantities or values on the interval scale. Summation or subtraction between their values makes sense.
Additive quantities from lesser to greater should be displayed as follows:
⎯ from left to right where a horizontal orientation is used;
⎯ from bottom to top where a vertical orientation is used;
⎯ clockwise rotation where a rotational orientation is used.
NOTE The category of additive quantities includes conceptual or abstract quantities such as complex numbers
and negative resistance.
EXAMPLE
(1)  Hor
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