ISO/TS 9241-411:2012

Ergonomics of human-system interaction — Part 411: Evaluation methods for the design of physical input devices

1 Scope This part of ISO 9241 specifies evaluation methods for the design of physical input devices for interactive systems. It provides guidance for the laboratory assessment of conformance with ISO 9241-410 for keyboards, mice, pucks, joysticks, trackballs, touch pads, tablets/overlays, touch-sensitive screens, and styli/light pens. Its provisions apply only to keyboards identified as "full-size" or "compact" by the manufacturer, but nevertheless could provide useful guidance in the design of other keyboards. It is not applicable to those of the requirements of ISO 9241-410 that relate to gesture- and voice-input systems.

Ergonomie de l'interaction homme-système — Partie 411: Méthodes d'évaluation de la conception des dispositifs d'entrée physiques

General Information

• Status: Published
• Publication Date: 18-Apr-2012
• ICS: 13.180 - Ergonomics
• ICS: 35.180 - IT Terminal and other peripheral equipment
• Technical Committee: ISO/TC 159/SC 4 - Ergonomics of human-system interaction
• Drafting Committee: ISO/TC 159/SC 4 - Ergonomics of human-system interaction
• Current Stage: 9093 - International Standard confirmed
• Completion Date: 07-Oct-2022

Relations

• Revises: ISO 9241-4:1998 - Ergonomic requirements for office work with visual display terminals (VDTs) — Part 4: Keyboard requirements
• Effective Date: 28-Apr-2012
• Revises: ISO 9241-9:2000 - Ergonomic requirements for office work with visual display terminals (VDTs) — Part 9: Requirements for non-keyboard input devices
• Effective Date: 28-Apr-2012

Standards Content (Sample)

TECHNICAL ISO/TS
SPECIFICATION 9241-411
First edition
2012-05-01

Ergonomics of human-system
interaction —
Part 411:
Evaluation methods for the design of
physical input devices
Ergonomie de l'interaction homme-système —
Partie 411: Méthodes d'évaluation de la conception des dispositifs
d'entrée physiques




Reference number
ISO/TS 9241-411:2012(E)
©
ISO 2012

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ISO/TS 9241-411:2012(E)

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ISO/TS 9241-411:2012(E)
Contents Page
Foreword . v
Introduction . viii
1  Scope . 1
2  Normative references . 1
3  Terms and definitions . 2
4  Guiding principles . 7
5  Evaluation methods . 7
5.1  Physical input devices in general . 7
5.2  Keyboards . 10
5.3  Mice . 22
5.4  Pucks . 25
5.5  Joysticks . 28
5.6  Trackballs . 31
5.7  Touchpads . 34
5.8  Tablets and overlays . 37
5.9  Styli and light-pens . 40
5.10  Touch-sensitive screens. 42
6  Conformance . 42
Annex A (informative) Overview of the ISO 9241 series . 43
Annex B (informative) Testing of efficiency and effectiveness . 44
Annex C (informative) Assessment of comfort . 51
Annex D (informative) Usability test for keyboards . 56
Bibliography . 62
Figures
Figure 1 — Side view of example joystick . 3
Figure 2 — Example of light-pen against display . 4
Figure 3 — Top view of example of tablet with graphic overlay . 4
Figure 4 — Top view examples of two types of puck . 5
Figure 5 — Side view of example of stylus over graphics tablet . 5
Figure 6 — Example of top view of trackball device with buttons . 6
Figure 7 — Illustration of flat, concave and convex keytops . 14
Figure 8 — Measurement of keytop width and depth . 14
Figure 9 — Measurement of key displacement . 14
Figure 10 — Relationship between key displacement and key force (ISO 9241-410:2008, Figure B.3) . 15
Figure 11 — Measurement of character height . 15
Figure 12 — Measurement of vertical and horizontal distance between two adjacent keys . 17
Figure 13 — Measurement of slope of keyboard . 18
Figure 14 — Numeric keypad layout . 18
Figure B.1 — Relationship of index of difficulty to time . 47
Figure B.2 — One-direction tapping task . 48
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ISO/TS 9241-411:2012(E)
Figure B.3 — Multi-directional pointing task . 49
Figure B.4 — Tracing task . 50

Tables
Table 1 — Measuring methods on physical input devices in general . 7
Table 2 — Requirements on the generic operability of keyboards . 10
Table 3 — Requirements for functional properties of full-size keyboards . 10
Table 4 — Requirements for sections and zones of full-size keyboards . 16
Table 5 — Requirements for the mechanical design of full-size keyboards . 17
Table 6 — Requirements for maintainability of full-size keyboards . 18
Table 7 — Requirements for documentation of full-size keyboards . 19
Table 8 — Requirements for design of keys of compact keyboards . 19
Table 9 — Requirements for sections and zones of compact keyboards . 20
Table 10 — Requirements for mechanical design of compact keyboards . 20
Table 11 — Requirements for maintainability of compact keyboards . 21
Table 12 — Requirements for documentation of compact keyboards . 22
Table 13 — Mouse design requirements . 22
Table 14 — Design requirements for pucks . 25
Table 15 — Design requirements for joysticks . 28
Table 16 — Design requirements for trackballs . 31
Table 17 — Design requirements for touchpads . 34
Table 18 — Design requirements for tablets and overlays . 37
Table 19 — Design requirements for styli and light-pens . 40
Table 20 — Design requirements for touch-sensitive screens . 42
Table A.1 — Structure of ISO 9241 — Ergonomics of human–system interaction . 43
Table B.1 — Task and condition variations . 45
Table C.1 — Independent rating scale . 52
Table C.2 — Dependent rating scale . 53
Table C.3 — Borg scale . 54
Table C.4 — Borg scale for arm, shoulder, and neck effort . 54
Table D.1 — Reflectance of surfaces . 58
Table D.2 — Independent rating scale . 60
Table D.3 — Example of material for data entry (English language) . 61

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ISO/TS 9241-411:2012(E)
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.
In other circumstances, particularly when there is an urgent market requirement for such documents, a
technical committee may decide to publish other types of document:
 an ISO Publicly Available Specification (ISO/PAS) represents an agreement between technical experts in
an ISO working group and is accepted for publication if it is approved by more than 50 % of the members
of the parent committee casting a vote;
 an ISO Technical Specification (ISO/TS) represents an agreement between the members of a technical
committee and is accepted for publication if it is approved by 2/3 of the members of the committee casting
a vote.
An ISO/PAS or ISO/TS is reviewed after three years in order to decide whether it will be confirmed for a
further three years, revised to become an International Standard, or withdrawn. If the ISO/PAS or ISO/TS is
confirmed, it is reviewed again after a further three years, at which time it must either be transformed into an
International Standard or be withdrawn.
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/TS 9241-411 was prepared by Technical Committee ISO/TC 159, Ergonomics, Subcommittee SC 4,
Ergonomics of human-system interaction.
This first edition of ISO/TS 9241-411, together with ISO 9241-400, ISO 9241-410 and ISO 9241-420, cancels
and replaces ISO 9241-4 and ISO 9241-9, technically revised as follows:
 terms and definitions from ISO 9241-4 and ISO 9241-9 have been transferred to ISO 9241-400;
 guiding principles, collected in ISO 9241-400, have been incorporated and unified so that they correspond
to the scope of the new ISO 9241 series;
 test methods taken from ISO 9241-4 and ISO 9241-9 have been reviewed and amended and new test
methods introduced and collected in annexes for greater convenience.
ISO/TS 9241 consists of the following parts, under the general title Ergonomic requirements for office work
with visual display terminals (VDTs):
 Part 1: General introduction
 Part 2: Guidance on task requirements
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ISO/TS 9241-411:2012(E)
 Part 5: Workstation layout and postural requirements
 Part 6: Guidance on the work environment
 Part 11: Guidance on usability
 Part 12: Presentation of information
 Part 13: User guidance
 Part 14: Menu dialogues
 Part 15: Command dialogues
 Part 16: Direct manipulation dialogues
 Part 17: Form filling dialogues
ISO 9241 also consists of the following parts, under the general title Ergonomics of human-system interaction:
 Part 20: Accessibility guidelines for information/communication technology (ICT) equipment and services
 Part 100: Introduction to standards related to software ergonomics [Technical Report]
 Part 110: Dialogue principles
 Part 129: Guidance on software individualization
 Part 143: Forms
 Part 151: Guidance on World Wide Web user interfaces
 Part 154: Interactive voice response (IVR) applications
 Part 171: Guidance on software accessibility
 Part 210: Human-centred design for interactive systems
 Part 300: Introduction to electronic visual display requirements
 Part 302: Terminology for electronic visual displays
 Part 303: Requirements for electronic visual displays
 Part 304: User performance test methods for electronic visual displays
 Part 305: Optical laboratory test methods for electronic visual displays
 Part 306: Field assessment methods for electronic visual displays
 Part 307: Analysis and compliance test methods for electronic visual displays
 Part 308: Surface-conduction electron-emitter displays (SED) [Technical Report]
 Part 309: Organic light-emitting diode (OLED) displays [Technical Report]
 Part 310: Visibility, aesthetics and ergonomics of pixel defects [Technical Report]
 Part 331: Optical characteristics of autosterescopic displays [Technical Report]
 Part 400: Principles and requirements for physical input devices
 Part 410: Design criteria for physical input devices
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ISO/TS 9241-411:2012(E)
 Part 411: Evaluation methods for the design of physical input devices [Technical Specification]
 Part 420: Selection of physical input devices
 Part 910: Framework for tactile and haptic interaction
 Part 920: Guidance on tactile and haptic interactions
The following parts are under preparation:
— Part 391: Requirements, analysis and compliance test methods for the reduction of photosensitive
seizures
User-interface elements, ergonomic requirements for the reduction of visual fatigue from stereoscopic images,
and the evaluation of tactile and haptic interactions are to form the subjects of future parts 161, 392 and 940.
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ISO/TS 9241-411:2012(E)
Introduction
Input devices are a means for users to enter data into interactive systems. Generally speaking, an input
device is a sensor that can detect changes in user behaviour (gestures, moving fingers, etc.) and transform
them into signals to be interpreted by the interactive system.
This part of ISO 9241 presents methods for the laboratory analysis and comparison of input devices for
interactive systems. It does not contain requirements for input devices, but provides the means for evaluating
conformance with the requirements of ISO 9241-410 for input devices such as keyboards, mice, pucks,
joysticks, trackballs, touch pads, tablets/overlays, touch-sensitive screens, and styli/light pens.
The target users of this part of ISO 9241 are manufacturers, product designers and test organizations
concerned with commercial input devices such as the physical input devices listed above.

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TECHNICAL SPECIFICATION ISO/TS 9241-411:2012(E)

Ergonomics of human-system interaction —
Part 411:
Evaluation methods for the design of physical input devices
1 Scope
This part of ISO 9241 specifies evaluation methods for the design of physical input devices for interactive
systems. It provides guidance for the laboratory assessment of conformance with ISO 9241-410 for
keyboards, mice, pucks, joysticks, trackballs, touch pads, tablets/overlays, touch-sensitive screens, and
styli/light pens. Its provisions apply only to keyboards identified as “full-size” or “compact” by the manufacturer,
but nevertheless could provide useful guidance in the design of other keyboards. It is not applicable to those
of the requirements of ISO 9241-410 that relate to gesture- and voice-input systems.
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.
1)
ISO 7000, Graphical symbols for use on equipment ― Index and synopsis
ISO 9241-5, Ergonomic requirements for office work with visual display terminals (VDTs) ― Part 5:
Workstation layout and postural requirements
ISO 9241-307, Ergonomics of human-system interaction ― Part 307: Analysis and compliance test methods
for electronic visual displays
ISO 9241-410:2008, Ergonomics of human-system interaction ― Part 410: Design criteria for physical input
devices
ISO/IEC 9995-1, Information technology ― Keyboard layouts for text and office systems ― Part 1: General
principles governing keyboard layouts
1)
IEC 60417, Graphical symbols for use on equipment

1) The database on Graphical Symbols for Use on Equipment contains the complete set of graphical symbols included in
ISO 7000 and IEC 60417: http://www.graphical-symbols.info/
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ISO/TS 9241-411:2012(E)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 9241-400 and ISO 9241-410 and
the following apply.
3.1
category
part of a system into which properties of entities can be arranged
[SOURCE: ISO 9241-410:2008; 3.2]
3.2
class
category of a property of a product with rank order
NOTE 1 Class 1 is the most, and class n the least, favourable category of a specific property of a product, where n is
the number of classes.
NOTE 2 An example of a property is durability of the legends of a key. If a key belongs to the highest class, it will fulfil
all requirements for the lower categories.
[SOURCE: ISO 9241-410:2008; 3.3]
3.3
compact keyboard
keyboard that features most properties of a full-size keyboard, with the editing section integrated into the
alphanumeric section
NOTE 1 A compact keyboard has no numeric section separate from the alpha keys.
NOTE 2 Compact is a term used to describe a keyboard that allows a mouse or other pointing device to be positioned
closer to the user as described in 9241-410, B.2.1.1. Some keyboards, for example keyboards with small dimensions as
used on portable devices, are neither full-size nor compact keyboards.
[SOURCE: ISO 9241-410:2008, 3.4, modified — Note 1 has been changed and Note 2 added.]
3.4
full-size keyboard
keyboard that comprises all sections and zones as described in ISO/IEC 9995-1
[SOURCE: ISO 9241-410:2008, 3.6]
3.5
housing
protective cover designed to contain or support a mechanical component
NOTE An input device is either integrated into its own housing or into another unit that comprises other functional
units (e.g. control desk, control panel, telephone).
[SOURCE: ISO 9241-410:2008, 3.11]
3.6
index of difficulty
I
D
measure of the user precision required in a task
NOTE The index of difficulty, I , is measured in bits, and is calculated for selection, pointing, or dragging tasks by
D
dw
I  log
D2
w

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ISO/TS 9241-411:2012(E)
and, for tracing tasks, by
d
I 
D
w

where
d is the distance of movement to the target;
w is the target width of the displayed target along the approach axis for selection, pointing or dragging tasks, and
perpendicular for tracing tasks.
[SOURCE: ISO 9241-410:2008; 3.12]
3.7
input device
user controlled device that transmits information to a system
[SOURCE: ISO 9241-400:2007; 3.6.3]
3.8
joystick
lever mounted in a fixed base used to control the movement of objects displayed on a screen
SEE: Figure 1.
[SOURCE: ISO 9241-400:2007; 3.6.4]

Figure 1 — Side view of example joystick
3.9
keypad
functional unit that comprises at least a group of keys dedicated and arranged for a given functionality and
possibly additional keys supporting related functionality
EXAMPLE Numeric keys, “Enter” key of keypad.
[SOURCE: ISO 9241-410:2008; 3.14]
3.10
light-pen
light sensitive input device that, when pointed onto a specific location on a display, identifies its position to the
system
SEE: Figure 2.
[SOURCE: ISO 9241-400:2007; 3.6.10]
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ISO/TS 9241-411:2012(E)

Figure 2 — Example of light-pen against display
3.11
mouse
computer input device having one or more buttons and capable of two dimensional rolling motion which can
drive a cursor on the display and performs a variety of selection options or commands
[SOURCE: ISO 9241-400:2007; 3.6.11]
3.12
neutral posture
posture which avoids the extremes of a joint’s range of motion or that is not near the end of the range of
motion for the particular joint
3.13
overlay
thin template on the surface of a tablet used to indicate the graphic functions available to the user
SEE: Figure 3.
[SOURCE: ISO 9241-400:2007; 3.6.13]

Key
1 graphic overlay
Figure 3 — Top view of example of tablet with graphic overlay
3.14
puck
hand-held device similar to a mouse but with a reticle view port and that is typically used with a digitizing tablet
SEE: Figure 4.
[SOURCE: ISO 9241-400:2007; 3.6.16]
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ISO/TS 9241-411:2012(E)

Figure 4 — Top view examples of two types of puck
3.15
section
functional groups within computer keyboards for which different rules for layouts can apply
NOTE Some sections of existing keyboards are arranged according to more-than-century-old conventions.
[SOURCE: ISO 9241-410:2008; 3.16]
3.16
stylus
pen-shaped pointing device which, when touched to a display or graphics tablet, can be used to draw images
on a display or select displayed objects, typically by depressing the stylus tip or actuating a button located
along the side of the stylus
SEE: See Figure 5.
[SOURCE: ISO 9241-400:2007; 3.6.23]

Figure 5 — Side view of example of stylus over graphics tablet
3.17
tablet
graphics tablet
special flat surface with an input device (such as a stylus or puck) for selection, drawing, or indicating the
position, of images to be displayed
[SOURCE: ISO 9241-400:2007; 3.6.24]
3.18
task precision
measure of the accuracy required for a pointing, selecting or dragging task primitive, quantified by the index of
difficulty
[SOURCE: ISO 9241-410:2008; 3.17]
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ISO/TS 9241-411:2012(E)
3.19
throughput
rate of information transfer when a user is operating an input device to control a pointer on a
display
NOTE The throughput is expressed in bits per second.
[SOURCE: ISO 9241-400:2007; 3.7.13]
3.20
touch sensitive screen
TSS
input device that produces a position and selection input signal from a finger touching, lifting off or moving
across a display
[SOURCE: ISO 9241-400:2007; 3.6.27]
3.21
touchpad
touch-sensitive pad that senses the position of a finger on its surface
[SOURCE: ISO 9241-410:2008; 3.18]
3.22
trackball
input device consisting of a ball in a fixed housing that can be rolled in any direction by the fingers to control
pointer movement
NOTE See Figure 6.
[SOURCE: ISO 9241-400:2007; 3.6.26]

Figure 6 — Example of top view of trackball device with buttons
3.23
zone
smaller unit within a section of a keyboard representing different functionality
EXAMPLE The layout of the alphanumeric keys for entering graphic characters (alphanumeric zone) grouped with
function and modifier keys such as “Ctrl”, “Alt”, “Tab” or “Backspace”.
[SOURCE: ISO 9241-410:2008; 3.20]
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ISO/TS 9241-411:2012(E)
4 Guiding principles
A structure is needed form compliance procedures and evaluation methods for physical input devices. The
aim of this structure is to clarify what requirements and classes (specified in ISO 9241-410) are relevant for
each intended application.
For this purpose the evaluation methods are outlined in the Tables 1 to 20. Each table addresses different
evaluation methods with three columns stating
 the clauses or subclauses referred to in ISO 9241-410, with the specific requirement being addressed,
 the pass/fail criterion based on the requirements reproduced from ISO 9241-410, and
 the recommended measuring methods to verify whether the requirement has been fulfilled.
Reporting should be done using the summarizing table shown in ISO 9241-410: 2008, Figure 1.
5 Evaluation methods
5.1 Physical input devices in general
Table 1 shows the measuring methods for physical input devices in general.
Table 1 — Measuring methods for physical input devices in general
Attribute in Pass/Fail criterion based on
ISO 9241-410: requirements and intended Measuring method
2008 context of use
Clause 5 The input device shall be Verify the conformance with the normative design requirements in the
usable for its designated relevant annex (ISO 9241-410:2008, Annexes B to J).
Usable for
purpose.
designated
purpose
Clause 5 The input device shall be
Verify the level of effort and satisfaction by measuring and
usable for its designated demonstrating comfort using the methods in Annex C.
Satisfactory
purpose. It is considered
level of
usable if users can achieve a
performance
satisfactory level of
performance on a given task
and maintain an acceptable
level of effort and satisfaction.
7.1 The intended use for a physical State:
input device shall be specified
 that the intended use is specified; or
Specification of
unless it is obvious or the
intended use
 that the intended use is for general purposes; or
device is designed for general
purpose use.
 that the intended use is obvious.
[Modified from ISO 9241-410]
7.1 The specification shall include Verify that the specification of the intended use of the device states the
technical conditions for the required technical conditions for the context of use.
Technical
context of use to be realized for
conditions for
a satisfactory use of the device
use
(e.g. operating system, driver,
support surface, etc.).

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ISO/TS 9241-411:2012(E)
Table 1 (continued)
Attribute in Pass/Fail criterion based on
...