EN ISO 9241-920:2024

Ergonomics of human-system interaction - Part 920: Tactile and haptic interactions (ISO 9241-920:2024)

This document specifies requirements and recommendations for tactile/haptic hardware and software interactions. It provides guidance on the design and selection of hardware, software and combinations of hardware and software interactions, including:
—     the design or use of tactile/haptic inputs, outputs and/or combinations of inputs and outputs, with general guidance on their design or use as well as on designing or using combinations of tactile and haptic interactions for use in combination with other modalities or as the exclusive mode of interaction;
—     the tactile/haptic encoding of information, including textual data, graphical data and controls;
—     the design of tactile/haptic objects;
—     the layout of tactile/haptic space;
—     interaction techniques.
The recommendations given in this document are applicable to a variety of tactile/haptic devices, representing the real world or virtual or mixed realities (e.g. exoskeletons, wearables, force feedback devices, touchables, tangibles) and stimulation types (e.g. acoustic radiation pressure, electrical muscle stimulation) and they can also be found in virtual and augmented environments.
This document provides general information about how various forms of tactile/haptic interaction can be applied to various user tasks.
This document does not include guidance on the role of walking in virtual or mixed realities for tactile/haptic interaction.
NOTE            It is recognized that some interactive scenarios can be constrained by the limitation that a real workspace is to be modelled in a virtual environment. Objects can be in suboptimal positions or conditions for tactile/haptic interaction by virtue of the situation being modelled.

Ergonomie der Mensch-System-Interaktion - Teil 920: Taktile und haptische Interaktionen (ISO 9241-920:2024)

Dieses Dokument spezifiziert Anforderungen an und Empfehlungen für taktile/haptische Hardware- und Software-Interaktionen. Er bietet eine Anleitung zur Gestaltung und Auswahl von Hardware, Software und Kombinationen aus Hardware- und Software-Interaktionen einschließlich
   Gestaltung oder Gebrauch von taktilen/haptischen Eingaben, Ausgaben und/oder Kombinationen von Eingaben und Ausgaben, mit einer allgemeinen Anleitung zu deren Gestaltung oder Gebrauch sowie zu taktilen und haptischen Interaktionen zur Gestaltung und zum Gebrauch in Kombination mit anderen Modalitäten oder als die ausschließliche Interaktionsmodalität;
   taktiler/haptischer Informationskodierung einschließlich Textdaten, Graphikdaten und Steuerelementen;
   die Gestaltung taktiler/haptischer Objekte;
   Anordnung des taktilen/haptischen Raums;
   Interaktionstechniken.
Die Empfehlungen in diesem Dokument sind für eine breite Palette von taktilen/haptischen Geräten, die die reale Welt, virtuelle Realitäten (VR, en: Virtual Reality) oder vermischte Realitäten (MR, en: Mixed Reality) (z. B. Exoskelette, Wearables, Geräte zur Kraftrückmeldung, Touchables, Tangibles) abbilden, und Stimulationsarten (z. B. Schallstrahlungsdruck, elektrische Muskelstimulation) anwendbar. Sie können auch in Virtual-Reality- und Augmented-Reality-Umgebungen Anwendung finden.
Dieses Dokument enthält allgemeine Informationen dazu, wie verschiedene taktile/haptische Interaktionsformen für verschiedene Benutzeraufgaben angewendet werden können.
Dieses Dokument umfasst keine Leitlinien zur Rolle des Sich-Bewegens in virtuellen oder gemischten Realitäten bei taktilen/haptischen Interaktionen.
ANMERKUNG   Es ist bekannt, dass einige interaktive Szenarien durch die Einschränkungen begrenzt sein können, die durch die Modellierung eines tatsächlichen Arbeitsplatzes in einer virtuellen Umgebung auferlegt werden. Objekte können sich aufgrund der zu modellierenden Situation an nicht optimalen Positionen oder in nicht optimalen Bedingungen für die taktile/haptische Interaktion befinden.

Ergonomie de l'interaction homme-système - Partie 920: Interactions tactiles et haptiques (ISO 9241-920:2024)

Le présent document donne des exigences et des recommandations ergonomiques relatives aux interactions tactiles/haptiques des matériels et des logiciels. Elle fournit des lignes directrices relatives à la conception et à la sélection des interactions des matériels et des logiciels ainsi que de leurs combinaisons, y compris:
—     la conception ou l'utilisation des entrées et sorties tactiles et haptiques et/ou des combinaisons d'entrées et sorties, avec des lignes directrices générales relatives à leur conception ou leur utilisation ainsi que des lignes directrices relatives à la conception ou à l’utilisation des combinaisons d'interactions tactiles et haptiques destinées à l'utilisation en combinaison avec d'autres modalités ou en tant que mode exclusif d'interaction;
—     le codage tactile/haptique d'informations, y compris les données textuelles, les données graphiques et les commandes;
—     la conception d'objets tactiles/haptiques;
—     l'aménagement de l'espace tactile/haptique;
—     les techniques d'interaction.
Les recommandations énoncées dans le présent document sont applicables à divers dispositifs tactiles/haptiques, représentant le monde réel ou des réalités virtuelles ou mixtes (par exemple, exosquelettes, appareils portables, dispositifs à retour d'effort, surfaces tactiles, tangibles) et divers types de stimulation (par exemple, pression de rayonnement acoustique, stimulation musculaire électrique) et pouvant également se trouver dans des environnements virtuels et augmentés.
Le présent document fournit des informations générales sur la manière dont diverses formes d'interaction tactile/haptique peuvent être appliquées à diverses tâches de l'utilisateur.
Le présent document ne comporte pas de recommandations concernant le rôle de la marche en réalité virtuelle ou mixte pour l'interaction tactile/haptique.
NOTE            Il est admis que certains scénarios interactifs peuvent être limités par le besoin de modéliser un espace de travail en un environnement virtuel. Les objets peuvent se trouver dans des positions ou conditions sous-optimales pour l'interaction tactile/haptique en raison de la situation à modéliser.

Ergonomija medsebojnega vpliva človek-sistem - 920. del: Taktilne in haptične interakcije (ISO 9241-920:2024)

Ta dokument določa zahteve in priporočila za taktilne/haptične interakcije s strojno ter programsko opremo. Podaja smernice glede načrtovanja in izbire interakcij s strojno in programsko opremo ter kombinacije interakcij med strojno in programsko opremo, vključno z naslednjim:
– načrtovanjem ali uporabo taktilnih/haptičnih vhodov, izhodov in/ali kombinacij vhodov in izhodov na podlagi splošnih smernic za njihovo načrtovanje oziroma uporabo ter načrtovanje ali uporabo kombinacij taktilnih in haptičnih interakcij za uporabo v povezavi z drugimi modalitetami ali kot izključni način interakcije;
– taktilnim/haptičnim šifriranjem informacij, vključno z besedilnimi in grafičnimi podatki ter krmilniki;
– načrtovanjem taktilnih/haptičnih objektov;
– postavitvijo taktilnega/haptičnega prostora;
– tehnikami za interakcijo.
Priporočila v tem dokumentu se uporabljajo za različne taktilne/haptične naprave, ki predstavljajo resnični svet ali navidezno ali kombinirano resničnost (npr. eksoskeleti, nosljive naprave, naprave s povratno silo, zaznavanje z dotikom, otipljivi predmeti) in vrste stimulacij (npr. akustični sevalni tlak, električna stimulacija
mišic) ter jih je mogoče najti tudi v navideznem in obogatenem okolju.
Ta dokument vsebuje splošne informacije o tem, kako je mogoče različne oblike taktilne/haptične interakcije uporabiti pri različnih uporabniških nalogah.
Ta dokument ne vključuje smernic glede vloge hoje v navidezni ali mešani resničnosti za taktilno/haptično interakcijo.
OPOMBA: Nekatere interaktivne scenarije lahko omejuje dejstvo, da je treba fizični delovni prostor modelirati v navideznem okolju. Zaradi situacije, ki se modelira, so lahko objekti v neoptimalnih položajih ali pogojih za taktilno/haptično interakcijo.

General Information

• Status: Published
• Publication Date: 22-Oct-2024
• ICS: 13.180 - Ergonomics
• ICS: 35.080 - Software
• ICS: 35.180 - IT Terminal and other peripheral equipment
• Technical Committee: CEN/TC 122 - Ergonomics
• Drafting Committee: CEN/TC 122/WG 5 - Ergonomics of human-computer interaction
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 23-Oct-2024
• Completion Date: 23-Oct-2024
• Ref Project: SIST EN ISO 9241-920:2025 - Ergonomics of human-system interaction - Part 920: Tactile and haptic interactions (ISO 9241-920:2024)

Relations

• Replaces: EN ISO 9241-920:2016 - Ergonomics of human-system interaction - Part 920: Guidance on tactile and haptic interactions (ISO 9241-920:2009)
• Effective Date: 18-Jan-2023

Standards Content (Sample)

SLOVENSKI STANDARD
01-januar-2025
Ergonomija medsebojnega vpliva človek-sistem - 920. del: Taktilne in haptične
interakcije (ISO 9241-920:2024)
Ergonomics of human-system interaction - Part 920: Tactile and haptic interactions (ISO
9241-920:2024)
Ergonomie der Mensch-System-Interaktion - Teil 920: Taktile und haptische
Interaktionen (ISO 9241-920:2024)
Ergonomie de l'interaction homme-système - Partie 920: Interactions tactiles et
haptiques (ISO 9241-920:2024)
Ta slovenski standard je istoveten z: EN ISO 9241-920:2024
ICS:
13.180 Ergonomija Ergonomics
35.180 Terminalska in druga IT Terminal and other
periferna oprema IT peripheral equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 9241-920
EUROPEAN STANDARD
NORME EUROPÉENNE
October 2024
EUROPÄISCHE NORM
ICS 13.180; 35.180 Supersedes EN ISO 9241-920:2016
English Version
Ergonomics of human-system interaction - Part 920:
Tactile and haptic interactions (ISO 9241-920:2024)
Ergonomie de l'interaction homme-système - Partie Ergonomie der Mensch-System-Interaktion - Teil 920:
920: Interactions tactiles et haptiques (ISO 9241- Taktile und haptische Interaktionen (ISO 9241-
920:2024) 920:2024)
This European Standard was approved by CEN on 17 October 2024.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 9241-920:2024 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 9241-920:2024) has been prepared by Technical Committee ISO/TC 159
"Ergonomics" in collaboration with Technical Committee CEN/TC 122 “Ergonomics” the secretariat of
which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by April 2025, and conflicting national standards shall be
withdrawn at the latest by April 2025.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 9241-920:2016.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 9241-920:2024 has been approved by CEN as EN ISO 9241-920:2024 without any
modification.
International
Standard
ISO 9241-920
Second edition
Ergonomics of human-system
2024-10
interaction —
Part 920:
Tactile and haptic interactions
Ergonomie de l'interaction homme-système —
Partie 920: Interactions tactiles et haptiques
Reference number
ISO 9241-920:2024(en) © ISO 2024

ISO 9241-920:2024(en)
© ISO 2024
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
ISO 9241-920:2024(en)
Contents Page
Foreword .vi
Introduction .vii
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Applying ISO 9241-920 . 2
4.1 Recommendations .2
4.2 Conformance .3
5 Tactile/haptic inputs, outputs and/or combinations . 3
5.1 General guidance on tactile/haptic inputs, outputs and/or combinations .3
5.1.1 Optimizing performance .3
5.1.2 Providing accessible information on tactile/haptic elements .3
5.1.3 Providing contextual information .3
5.1.4 Identifying system state .4
5.1.5 Minimizing fatigue . . .4
5.1.6 Providing alternative input methods .4
5.1.7 Maintaining coherence between modalities .4
5.1.8 Combining modalities .5
5.1.9 Presenting realistic experiences .5
5.1.10 Isolation of individual interface elements .5
5.2 Intentional individualization .6
5.2.1 Enabling users to change modalities .6
5.2.2 Enabling force feedback override .6
5.2.3 Force feedback control .6
5.2.4 Force feedback indication .6
5.2.5 Enabling users to limit force feedback .6
5.2.6 Enabling users to individualize tactile/haptic parameters .6
5.3 Unintentional user perceptions .7
5.3.1 Limiting acoustic output of tactile/haptic display .7
5.3.2 Limiting heat gain of contact surface.7
5.3.3 Avoiding sensory adaptation .7
5.3.4 Recovering from sensory adaptation .7
5.3.5 Avoiding unintended perceptual illusions .7
5.3.6 Preventing temporal masking .8
6 Attributes of tactile and haptic encoding of information . 8
6.1 High level guidance on tactile/haptic encoding of information .8
6.1.1 Using familiar tactile/haptic patterns .8
6.1.2 Making tactile/haptic encoding obvious .8
6.1.3 Conformity to user expectations .8
6.1.4 Using sensory substitution .8
6.1.5 Using appropriate spatial addressability and resolution . .9
6.1.6 Using tactile apparent location .9
6.1.7 Tactile display of high spatial resolution .9
6.1.8 Using higher addressability for trained users .9
6.1.9 Using tactile apparent motion .9
6.1.10 Preventing spatial masking .9
6.2 Guidance on specific tactile/haptic attributes for encoding information .10
6.2.1 Selecting properties for encoding information .10
6.2.2 Discriminating between attribute values .11
6.2.3 Limiting the number of attribute values .11
6.2.4 Combining properties .11
6.2.5 Limiting complexity.11
6.2.6 Encoding by object shape .11

iii
ISO 9241-920:2024(en)
6.2.7 Encoding information by temporal pattern .11
6.2.8 Encoding information using vibration amplitude . 12
6.2.9 Encoding information by vibration frequency . 12
6.2.10 Encoding by body location . 12
6.2.11 Encoding by temperature . 12
6.2.12 Encoding by thermal conductivity . 12
6.2.13 Identifying information values . 13
6.2.14 Encoding information using electrotactile amplitude . 13
6.2.15 Encoding information by electrotactile frequency . 13
6.2.16 Waveform for electrotactile feedback . 13
6.2.17 Polarity of electrotactile output . 13
7 Content-specific tactile/haptic encoding .13
7.1 Encoding and presenting text data. 13
7.1.1 Text presentation speed . 13
7.1.2 Text presentation layout . 13
7.1.3 Text shape presentation . .14
7.1.4 Text presentation surface contrast .14
7.1.5 Text presentation size .14
7.2 Encoding and presenting data through information haptification .14
7.2.1 Displaying information in tactile/haptic graphics .14
7.2.2 Complexity of information haptification .14
7.2.3 Maintaining orientation in information haptification .14
7.2.4 Perceivability of information haptification . 15
7.2.5 Texture discriminability in information haptification . 15
7.2.6 Consistency of information haptification . 15
7.2.7 Combinations of text and graphics in information haptification . 15
7.2.8 Learnability of information haptification . 15
7.2.9 Using grids on tactile/haptic graphs . 15
7.2.10 Using landmarks in tactile/haptic maps . 15
7.2.11 Providing scales for tactile/haptic maps .16
7.3 Encoding and using controls .16
7.3.1 Using tactile/haptic controls .16
7.3.2 Using size and spacing of controls to avoid accidental activation .16
7.3.3 Use of electrodes .16
7.3.4 Avoiding difficult control actions .16
7.3.5 Using force to avoid accidental activation .16
7.3.6 Support user safety .17
7.3.7 Interacting with virtual controls .17
8 Design of tactile/haptic objects and space .18
8.1 Tactile/haptic display spaces .18
8.1.1 Ease of perceiving multiple tactile/haptic objects .18
8.1.2 Ease of identifying adjacent tactile/haptic objects .18
8.1.3 Maintaining separation between surfaces of objects .18
8.1.4 Separating tactile/haptic elements .18
8.1.5 Using consistent labels .18
8.1.6 Tactile/haptic label design .18
8.1.7 Avoiding empty spaces.19
8.1.8 Avoiding volume limits .19
8.1.9 Avoiding falling out of the tactile/haptic space .19
8.2 Objects .19
8.2.1 Using appropriate object size .19
8.2.2 Creating tactile/haptic symbols from visual symbols .19
8.2.3 Discriminating tactile/haptic symbols .19
8.2.4 Tactile/haptic object angles . 20
8.2.5 Tactile/haptic object corners . 20
9 Interaction .20
9.1 Navigating tactile/haptic space . 20

iv
ISO 9241-920:2024(en)
9.1.1 Providing navigation information . 20
9.1.2 Supporting path planning . 20
9.1.3 Providing well-designed paths . 20
9.1.4 Making landmarks easy to identify and recognize . 20
9.1.5 Providing appropriate navigation techniques . 20
9.1.6 Providing navigational aids . .21
9.1.7 Understanding the tactile/haptic space .21
9.1.8 Supporting exploratory strategies (procedures) .21
9.2 Reconfiguration .21
9.2.1 Reconfiguring the tactile/haptic space.21
9.2.2 System-initiated reconfigurations .21
9.2.3 Maintaining user’s sense of location during reconfiguration . 22
9.3 Interaction techniques. 22
9.3.1 Implementing interaction techniques . 22
9.3.2 Avoiding unintended oscillation . 22
Bibliography .23

v
ISO 9241-920:2024(en)
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.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO’s adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 159, Ergonomics, Subcommittee SC 4,
Ergonomics of human-system interaction, in collaboration with the European Committee for Standardization
(CEN) Technical Committee CEN/TC 122, Ergonomics, in accordance with the Agreement on technical
cooperation between ISO and CEN (Vienna Agreement).
This second edition cancels and replaces the first edition (ISO 9241-920:2009), which has been technically
revised.
The main change is as follows:
— The document has been updated to reflect newer research in tactile/haptic interactions.
A list of all parts in the ISO 9241 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

vi
ISO 9241-920:2024(en)
Introduction
Tactile and haptic interactions have become increasingly important interaction modalities. Mobile
interaction relies on gesture-based touch interaction and tactile/haptic control devices and can utilize
vibration-based displays as one of several ways to provide information or experiences to the user. Touch,
vibration and tactile/haptic interactions are also found in special-purpose computing environments (e.g.
simulation, remote control or surgery) and in assistive technologies.
While considerable research exists, a lack of ergonomic standards in this area can possibly result in systems
being developed without sufficient concern for either ergonomics or interoperability, leading to serious
difficulties related to ergonomics for users of multiple incompatible or conflicting tactile/haptic devices or
applications.
This document provides ergonomics requirements and recommendations for tactile and haptic hardware
and software interactions, including guidance related to the design and evaluation of hardware, software
and combinations of hardware and software interactions. The guidelines are not technology-dependent and
will also be applicable to future technologies.
ISO 9241-910 provides a common set of terms, definitions and descriptions of the various concepts central
to designing and using tactile/haptic interactions. It also provides an overview of the range of tactile/haptic
applications, objects, attributes and interactions.
ISO 9241-940 provides ways of evaluating tactile/haptic interactions for their usability, the validation of
requirements and the verification that systems meet the requirements.
ISO 9241-960 focuses on gestures as a specific type of tactile/haptic interaction and describes their features
and usability requirements. Information on gesture-based interfaces can be found in the ISO/IEC 30113
series. Information on contactless gestures can be found in ISO TS 9241-430.
For guidance and recommendations on the accessibility of tactile/haptic interactions, including information
on the use of braille, see ISO 9241-971. It does not provide recommendations specific to braille but can apply
to interactions that make use of braille.

vii
International Standard ISO 9241-920:2024(en)
Ergonomics of human-system interaction —
Part 920:
Tactile and haptic interactions
1 Scope
This document specifies requirements and recommendations for tactile/haptic hardware and software
interactions. It provides guidance on the design and selection of hardware, software and combinations of
hardware and software interactions, including:
— the design or use of tactile/haptic inputs, outputs and/or combinations of inputs and outputs, with
general guidance on their design or use as well as on designing or using combinations of tactile and
haptic interactions for use in combination with other modalities or as the exclusive mode of interaction;
— the tactile/haptic encoding of information, including textual data, graphical data and controls;
— the design of tactile/haptic objects;
— the layout of tactile/haptic space;
— interaction techniques.
The recommendations given in this document are applicable to a variety of tactile/haptic devices,
representing the real world or virtual or mixed realities (e.g. exoskeletons, wearables, force feedback
devices, touchables, tangibles) and stimulation types (e.g. acoustic radiation pressure, electrical muscle
stimulation) and they can also be found in virtual and augmented environments.
This document provides general information about how various forms of tactile/haptic interaction can be
applied to various user tasks.
This document does not include guidance on the role of walking in virtual or mixed realities for tactile/
haptic interaction.
NOTE It is recognized that some interactive scenarios can be constrained by the limitation that a real workspace
is to be modelled in a virtual environment. Objects can be in suboptimal positions or conditions for tactile/haptic
interaction by virtue of the situation being modelled.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/

ISO 9241-920:2024(en)
3.1
electrotactile feedback
delivering tactile/haptic sensations to the user by excitation of the cutaneous nerve fibres with electric current
3.2
electrostatic feedback
delivering tactile/haptic sensations of friction to the user by electric force
3.3
information haptification
presentation and exploration of data and their relations through tactile/haptic interaction
3.4
sensory substitution
information usually analysed by one sense provided through another sense
EXAMPLE 1 Tactile sensations can substitute for visual input, e.g. when visible text is transcribed into tactile
sensations through braille for an individual who is blind.
EXAMPLE 2 A visual diagram is substituted by an audible representation of the information in the diagram.
Note 1 to entry: Sensory substitution allows the system to provide the same information in more than one modality. It
is not a substitution on the part of human perception. For example, persons who experience synaesthesia, which is an
involuntary association of one sense with another or one sensory attribute with another, sometimes experience colour
when hearing sound.
3.5
tactile
appertaining to touch
[SOURCE: ISO 9241-910:2011, 2.5]
3.6
haptic, adj
appertaining to haptics (3.7)
Note 1 to entry: While there is no difference between haptic and tactile (3.5) in most dictionary definitions, in the area
of haptics, researchers and developers use haptic to include all haptic sensations, while tactile is limited to mechanical
stimulation of the skin. In ISO 9241, the word haptic covers all touch sensations and tactile is used in a more specific
manner. Also, both terms can be used together to assist in searches.
[SOURCE: ISO 9241-910:2011, 2.2]
3.7
haptics, noun
sensory and/or motor activity based in the skin, muscles, joints and tendons
Note 1 to entry: Haptics consists of two parts: touch and kinaesthesis.
[SOURCE: ISO 9241-910:2011, 2.1]
4 Applying ISO 9241-920
4.1 Recommendations
The recommendations given in Clauses 5 to 9 should be evaluated for their applicability. The applicable
recommendations should be implemented, unless there is evidence that to do so would cause deviation from
the design objectives.
ISO 9241-920:2024(en)
4.2 Conformance
If it is claimed that a product conforms to the applicable requirements and recommendations in this
document, then the procedures used to establish conformance of the product shall be specified. The level of
detail of the specification is a matter of negotiation between the involved parties.
NOTE Guidance on the evaluation of tactile/haptic products can be found in ISO 9241-940.
5 Tactile/haptic inputs, outputs and/or combinations
5.1 General guidance on tactile/haptic inputs, outputs and/or combinations
5.1.1 Optimizing performance
The system should be optimized to take into account the following:
a) the accuracy of available devices, the accuracy of the user and the required accuracy of the task;
b) the ability of a user to control the velocity and the force (including direction) involved in operations;
NOTE 1 High speed of user actions is inconsistent with accurate control of force, and vice versa.
c) active exploration over passive exploration, when appropriate;
NOTE 2 This can increase kinaesthetic perception.
d) extended contact area;
NOTE 3 Extended area can be needed depending on the part of the body in contact with a tactile/haptic device.
EXAMPLE 1 The back does not resolve two-point discrimination as easily as the fingertip.
e) multiple point-of-contact operation, when possible and appropriate;
NOTE 4 This can reduce errors and improve tactile perception.
EXAMPLE 2 The use of two hands in reading braille can improve efficiency.
f) the overall amount and distributed nature of cognitive and sensory task demands.
NOTE 5 Effectiveness of tactile and haptic inputs is affected by overall workload, conflict among multi-task
demands and/or overload or decrement of particular sensory information channels.
5.1.2 Providing accessible information on tactile/haptic elements
The system should provide accessible alternatives of all tactile/haptic user interface elements, whether
those alternatives are automatically presented or not.
NOTE An accessible alternative can describe the user interface element through text, sound labels, synthetic
speech or sign language or as braille text.
EXAMPLE Touchscreen buttons with spoken descriptions.
5.1.3 Providing contextual information
The system should provide a context to help the user to understand the meaning of the tactile/haptic
perception and the environment or program.
NOTE 1 Contextual information that is helpful includes information about the purpose of the program, and
information about possibilities and pitfalls in the environment.

ISO 9241-920:2024(en)
NOTE 2 Contextual information can be in the form of a short message, such as a caption under an image or model,
and presented as speech, sign language or braille.
EXAMPLE 1 An automobile's steering wheel vibrates to provide a tactile cue alert for lane deviation. A visual alert
icon on the dashboard simultaneously provides the driver contextual information about why the wheel is vibrating.
EXAMPLE 2 Tactile/haptic cues for presenting information can have an optional auditory cue.
5.1.4 Identifying system state
The system should provide information that allows the user to know which task or function is active.
5.1.5 Minimizing fatigue
The system should:
a) ensure user comfort over extended periods of time;
b) avoid or minimize user fatigue.
NOTE Minimization of tactile/haptic fatigue can be achieved by:
— careful choice of body location for stimulation;
— careful choice of method of contact with the body;
— careful choice of stimulus frequency;
— choosing the lowest effective magnitude of the stimulus;
— reducing minute, precise joint rotations, particularly at proximal segments;
— not using static positions at or near the end of the range of motion;
— not expecting users to overreach to discover the full extent of the display.
5.1.6 Providing alternative input methods
The system should enable users to accomplish the same function in multiple ways. If the task is a fine
manipulation task, alternative means should be offered that require less movement precision to enable this
type of interaction.
NOTE 1 The most efficient, logical or effective input or control mechanism for a majority of users can potentially be
difficult, if not impossible, for individual users with differing abilities to use.
EXAMPLE One-handed (either left or right) operation is used.
NOTE 2 Changing the scale of the virtual environment can make fine motor tasks easier.
5.1.7 Maintaining coherence between modalities
The system should maintain coherence, where appropriate, between the tactile/haptic modality and other
modalities, including the descriptions of actions.
NOTE 1 The visual perception of objects can bias, and be biased by, the tactile/haptic perception of objects. This
can also occur between the tactile/haptic modality and other modalities.
NOTE 2 Aspects of coherence (amodal attributes) can include:
— size;
— orientation;
— shape;
ISO 9241-920:2024(en)
— mapping;
— separation of objects;
— temporal presentation.
NOTE 3 Coherence also includes the relative location of on-screen controls, including the directions in which they
can be moved.
NOTE 4 Incoherence can cause confusion and control instabilities in multimodal systems.
5.1.8 Combining modalities
Combining modalities is recommended, as it supports usability and can make systems more accessible.
Some effects of combining modalities are:
a) reinforcement of information obtained from purely tactile/haptic interactions;
EXAMPLE 1 A sound when an object is struck.
b) provision of additional information not presented via tactile/haptic interactions;
NOTE 1 The resulting combinations can enhance spatial memory and the identification and exploration of
objects and their attributes.
EXAMPLE 2 Information on the colour of an object.
NOTE 2 Combination of modalitie
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