ergonomics user interface standards: are they more trouble than they are worth?
TRANSCRIPT
This article was downloaded by: [Linnaeus University]On: 05 October 2014, At: 20:48Publisher: Taylor & FrancisInforma Ltd Registered in England and Wales Registered Number:1072954 Registered office: Mortimer House, 37-41 Mortimer Street,London W1T 3JH, UK
ErgonomicsPublication details, including instructions forauthors and subscription information:http://www.tandfonline.com/loi/terg20
Ergonomics user interfacestandards: are they moretrouble than they areworth?Tom Stewart aa System Concepts LimitedPublished online: 10 Nov 2010.
To cite this article: Tom Stewart (2000) Ergonomics user interface standards:are they more trouble than they are worth?, Ergonomics, 43:7, 1030-1044, DOI:10.1080/001401300409206
To link to this article: http://dx.doi.org/10.1080/001401300409206
PLEASE SCROLL DOWN FOR ARTICLE
Taylor & Francis makes every effort to ensure the accuracy of allthe information (the “Content”) contained in the publications on ourplatform. However, Taylor & Francis, our agents, and our licensorsmake no representations or warranties whatsoever as to the accuracy,completeness, or suitability for any purpose of the Content. Anyopinions and views expressed in this publication are the opinions andviews of the authors, and are not the views of or endorsed by Taylor& Francis. The accuracy of the Content should not be relied upon andshould be independently verified with primary sources of information.Taylor and Francis shall not be liable for any losses, actions, claims,proceedings, demands, costs, expenses, damages, and other liabilitieswhatsoever or howsoever caused arising directly or indirectly inconnection with, in relation to or arising out of the use of the Content.
This article may be used for research, teaching, and private studypurposes. Any substantial or systematic reproduction, redistribution,
reselling, loan, sub-licensing, systematic supply, or distribution in anyform to anyone is expressly forbidden. Terms & Conditions of accessand use can be found at http://www.tandfonline.com/page/terms-and-conditions
Dow
nloa
ded
by [
Lin
naeu
s U
nive
rsity
] at
20:
48 0
5 O
ctob
er 2
014
Ergonomics user interface standards: are they more troublethan they are worth?
TOM STEWART*
System Concepts Limited, 2 Savoy Court, Strand, London WC2R 0EZ, UK
Keywords: User interface; Standards; ISO; VDT; Usability.
The purpose of this paper is to review the history, progress and results of one areaof international standardizationÐ the ergonomics of human-system interaction. Itis a personal perspective based on my experiences as Chairman of ISO/TC159/SC4 over the past 17 years. The paper starts with some historical background andsummarizes the main work of the Committee. It then identi® es ® ve areas wherethe results of the standardization work could have been more successful anddiscusses what went wrong. These problems include the long time-scale fordevelopment, how the standards were misunderstood, how political the processcan be, how we may have tried to be too clever and how the abundance of help attimes may have been a problem. The paper concludes with an explanation of whythe activity and the results were not all bad. The ® ve positive areas include thebene® ts that can come from the slow pace of the work, the bene® ts of structureand formality, why standards do not have to be restrictive, how the standardsthemselves are only part of the outcome and how being a truly internationalexperience makes it all worthwhile.
1. Introduction
The purpose of this paper is to review the history, progress and results of one area of
international standardizationÐ the ergonomics of human-system interactionÐ overthe past 17 years. Although I will attempt to put the case for and the case against
standards, it would be foolish for me to suggest that this will be an impartial review.
I would not have spent and continue to spend a signi® cant portion of my working
life developing standards if I were not basically convinced that the e� ort was
worthwhile. None the less, I would argue that although many people crit icizestandards (sometimes correctly), no-one is more aware of the shortcomings of the
process (and the end results) than those who struggle to make it work.
I am therefore delighted to have been given the opportunity by the Human
Factors and Ergonomics Society and the International Ergonomics Association to
stand back and take another look at our standardization work. Of course, I have
said much of this before in various forms and to di� erent audiences (Stewart 1998,1999). Anyone who read or attended these earlier sessions will be familiar with some
of the argumentsÐ it is di� cult to ® nd new ways to describe the same issues and the
same standardsÐ none the less this is a major opportunity to pull it all together and
*Author for correspondence. e-mail: [email protected]
ERGONOMICS, 2000, VOL. 43, NO. 7, 1030±1044
Ergonomics ISSN 0014-0139 print/ISSN 1366-584 7 online Ó 2000 Taylor & Francis Ltdhttp://www.tandf.co.uk/journals
Dow
nloa
ded
by [
Lin
naeu
s U
nive
rsity
] at
20:
48 0
5 O
ctob
er 2
014
to give a more considered overview. However, before progressing, I would like to
make it clear which standardization activities I am reviewingÐ there are more than
you might suspect.
1.1. Standards are such fun that everyone wants one of their ownIn most people’s minds, one of the most basic and fundamental objectives of
standardization is to minimize unnecessary variations. Ideally, for any product
category, there is one standard that should be satis® ed and products which meet that
standard give their owners or users some reassurance about quality or about what
standards makers refer to as interoperability. Thus yachtsmen in Europe who buy alifejacket which meets EN 396 (EN 396: 1994 Lifejackets and personal buoyancy
aids) might reasonably expect it to keep them a¯ oat if they have the misfortune to
fall overboard. Similarly, an o� ce manager in the USA who orders A4 paper for his
photocopiers (ISO 216:1975) might reasonably expect paper which meets that
standard to ® t even though it is not the typical size used locally.
This brings us to a rather important point. It is often di� cult to achieve a singleagreed standard and a common solution is to have more than one standard. An
obvious example concerns paper size where there is the ISO A series (A0, A1, etc.),
the ISO B series (B0, B1, etc.) as well as US sizes (legal, letter, etc.). Although this
solves the standards makers’ problems in agreeing on a single standard, it is an
endless source of frustration for users of the standard as anyone who has forgottento check the paper source in an e-mailed document can testify.
However, there is another reason why there are more standards than one might
imagine, especially when it comes to user interface design issues. The reason is that
computer technology forms the basis of many di� erent industries and standards can
have an important impact on market success.In my corner of the standardization world as Chairman of ISO/TC 159/SC4
Ergonomics of Human System Interaction, I have enjoyed collaboration with a
number of other usability standards bodies including:
· ISO/IEC JTC1/SC35 Cultural and Linguistic Adaptability (was SC18/WG9
User System Interfaces and Symbols)
· ETSI/TC-HF
· IEEE P1201.2 User Interface Drivability
· ECMA TC 35 User System Interface
· CEN/TC122/WG5 Ergonomics of VDTs.
It is not just at the international level that there appears to be some duplication. In
the UK, the British Standards Institution mirror committee to SC4 published an
early version of the ® rst six parts of ISO 9241 as a British Standard, BS 7179:1990.
The prime reason for this was to provide early guidance for employers of users of
visual displays who wanted to use standards to help them to select equipment whichmet the requirements in the Schedule to the Health and Safety (D isplay Screen
Equipment) Regulations 1992. These regulations are the UK implementation of a
European Community Directive on the minimum safety and health requirements for
work with display screen equipment (90/270/EEC). Of course, as a spin-o� the
British Standards Institution (BSI) was able to generate revenue from selling these
standards several years before the various parts of ISO 9241 became available asBritish Standards.
1031Ergonomics user interface standards
Dow
nloa
ded
by [
Lin
naeu
s U
nive
rsity
] at
20:
48 0
5 O
ctob
er 2
014
A similar process has taken place in the USA with the Human Factors and
Ergonomics Society (HFES) developing HFS 100 on Visual Display Terminal
Ergonomics as an ANSI-authorized Standards Developing Organization. More
recently there are two HFES standards development committees working on HFES
100 (a new version of HFS 100) and on HFES 200, which addresses user interfaceissues. It includes sections on accessibility, voice and telephony applications, colour
and presentation, and slightly re-written parts of the software parts of ISO 9241.
Although in this paper, I will focus solely on the work of ISO/TC159/SC4 The
Ergonomics of Human System Interaction, many of the comments are relevant to
other standards activit ies.
1.2. How the International Organization for Standardization worksThe International Organization for Standardization (ISO) comprises national
standards bodies from member states (see www.iso.ch for more information). Its
work is conducted by technical committees and sub-committees which meet every
year or so and are attended by formal delegations from participating members ofthat committee. In practice, the technical work takes place in Working Groups of
experts nominated by national standards committees who are expected to act as
independent experts. The standards are developed over a period of several years and
in the early stages the published documents may change dramatically from version to
version until consensus is reached (usually within a Working Group of experts). Asthe standard becomes more mature (from the Committee Draft Stage onwards),
formal voting takes place (usually within the parent sub-committee) and the draft
documents provide a good indication of what the ® nal standard is likely to look like.
Table 1 shows the main stages of ISO standards development.
1.3. How this paper is structuredIn § 2, the origins of ISO/TC159/SC4 and the work that has led to its main standards
published today, primarily the ISO 9241 series, are described. Section 3 explains how
we thought that ISO 9241 would be used to support system design decisions. I review
all the problems and issues that have led some to believe that standards are just too
Table 1. The main stages of ISO standards development.
WI Work ItemÐ an approved and recognized topic for a working group to beaddressing, which should lead to one or more published standards.
WD Working DraftÐ a partial or complete ® rst draft of the text of the proposedstandard.
CD Committee DraftÐ a document circulated for comment and approval within thecommittee working on it and the national mirror committees. Voting and approvalis required for the document to reach the next stage.
DIS Draft International StandardÐ a draft standard which is circulated widely forpublic comment via national standards bodies. Voting and approval is required forthe draft to reach the ® nal stage.
FDIS Final Draft International StandardÐ the ® nal draft is circulated for formal votingfor adoption as an International Standard.
IS International Standard. The ® nal published standard.
Documents may be reissued as further CDs and DISs.
1032 T . Stewart
Dow
nloa
ded
by [
Lin
naeu
s U
nive
rsity
] at
20:
48 0
5 O
ctob
er 2
014
much trouble in § 4. In § 5, I argue that the bene® ts of the standards and, in some
ways more importantly, of the standardization process outweigh these admitted
disadvantages. F inally, I outline how this area of standards work might develop in
the future.
2. The origins of ISO/TC159/SC4
In the late 1970s, there was growing concern about the ergonomics of visual display
terminals (also called visual display units). The prime concern at that time concerned
the possibility that prolonged use (especially of displays with poor image quality) might
cause deterioration in the eyesight of users. However, since then several studies haveshown that ageing causes the main e� ect on eyesight and since display screen work can
be visually demanding, many people only discover this deterioration when they
experience discomfort from intensive display screen use. This can incorrectly lead them
to attribute their need for glasses to their use of display screens.
When a new work item to address this concern was proposed, the Information
Technology Committee decided that this was a suitable topic for the recently formedErgonomics Committee ISO/TC 159. The work item was allocated to the Sub-
committee ISO/TC 159/SC4 Signals and Controls and an inaugural meeting was held
at BSI in Manchester in 1983. The meeting was well attended with delegates from many
countries and a few key decisions were made.
At that time, there was a proliferation of o� ce-based systems and we decided tofocus on o� ce tasks (word processing, spreadsheets, etc.) rather than try to include
Computer Aided Design (CAD) or process control applications. We also decided that
we would need a multi-part standard to cover the wide range of ergonomics issues
which we believed needed to be addressed in order to improve the ergonomics of
display screen work. Six initial parts were identi® ed and working groups wereestablished (table 2). At the end of that ® rst meeting, one of the distinguished
participants, Professor Bengt Knave from Sweden, was heard to complain that we had
been meeting for three days and still had not standardized anything. Little did any of us
realize that it would be nearly 7 years before the ® rst parts of ISO 9241 would be
published and that it would take us until the end of the century to publish all 17 parts.
Table 3 shows the 17 parts of ISO 9241 Ergonomic requirements for o� ce workwith visual display terminals (VDTs). Table 4 shows the other human-system
interaction standards for which ISO/TC 159/SC4 is responsible.
3. How we intended ISO 9241 to be used
The structure of the standard was decided at a time when there were cleardistinctions between hardware and software and monochrome Cathode Ray Tube
(CRT) displays were the norm. The ® rst six parts were therefore primarily concerned
Table 2. Working Groups of ISO/TC159/SC4.
WG1 Fundamentals of controls and signalling methodsWG2 Visual display requirementsWG3 Control, workplace and environmental requirementsWG4 Task requirements (disbanded)WG5 Software ergonomics and human-computer dialogueWG6 Human-centred design processes for interactive systemsWG7 Ergonomics design of control centres
1033Ergonomics user interface standards
Dow
nloa
ded
by [
Lin
naeu
s U
nive
rsity
] at
20:
48 0
5 O
ctob
er 2
014
Table 3. Parts and status of ISO 9241. Ergonomics requirements for o� ce work with visualdisplay terminals (VDTs).
Responsible Status atISO 9241 Working Group Dec 1999
Part 1Part 2Part 3Part 4Part 5Part 6Part 7Part 8Part 9Part 10Part 11Part 12Part 13Part 14Part 15Part 16Part 17
General introductionGuidance on task requirementsVisual display requirementsKeyboard requirementsWorkstation layout and postural requirementsGuidance on the work environmentRequirements for displays with re¯ ectionsRequirements for displayed coloursRequirements for non-keyboard input devicesDialogue principlesGuidance on usabilityPresentation of informationUser guidanceMenu dialoguesCommand dialoguesDirect manipulation dialoguesForm ® lling dialogues
WG6WG4 (disbanded)
WG2WG3WG3WG3WG2WG2WG3WG5WG5WG5WG5WG5WG5WG5WG5
ISISISISISISISIS
FDISISISISISISISISIS
Table 4. Other human system interaction standards for which ISO/TC 159/SC4 isresponsible.
ISOResponsible
WorkingStatusat Dec
Standards Group 1999
13406-1
13406-2
14915-1
14915-214915-314915-4TS 1607113407
TS 16982TR 1852911064-111064-211064-311064-411064-511064-611064-711064-8
Ergonomics requirements for ¯ at panel displaysÐ IntroductionErgonomics requirements for ¯ at panel displaysÐ Ergonomics requirementsSoftware ergonomics for multi-madia interfacesÐ Design principles and frameworkMultimedia control and navigationMedia selection and combinationDomain-speci® c multimedia aspectsAccessibilityHuman-centred design processes for interactivesystemsUsability methods supporting HC designHuman-centred lifecycle process descriptionsPrinciples for the design of control centresPrinciples of control suite arrangementControl room layoutWorkstation layout and dimensionsDisplays and controlsEnvironmental requirements for control roomsPrinciples for the evaluation of control centresErgonomics requirements for speci® capplications
WG2
WG2
WG5
WG5WG5WG5WG5WG6
WG6WG6WG8WG8WG8WG8WG8WG8WG8WG8
IS
FDIS
DIS
2nd CDDISWIWDIS
CDTR
FDISFDIS
ISWDWDWDWIWI
1034 T . Stewart
Dow
nloa
ded
by [
Lin
naeu
s U
nive
rsity
] at
20:
48 0
5 O
ctob
er 2
014
with hardware (which, in our na õ È veteÂwe thought would be easier and less
contentious to standardize). However, even within this hardware domain, we
recognized the importance of job and task design in ensuring that users could work
safely, comfortably and e� cientlyÐ so Part 2 was inserted before the more technical
hardware oriented parts.Later, software parts (Parts 10 to 17) were added, re¯ ecting the di� erent styles of
user system interaction which were available at the time and additional hardware parts
were added to deal with re¯ ections (Part 7), colour displays (Part 8) and non-keyboard
input devices, e.g. the mouse (Part 9). The structure therefore re¯ ected the practicalities
and history of standard making and unfortunately is not very user-centred (one of thekey principles of ergonomics).
Although we did not make it explicit at the time, we had an underlying set of
assumptions about human-computer interaction (HCI) design activities and how the
standards would support these. These activities included:
· Analysing and de® ning system requirements
· Designing user-system dialogues and interface navigation
· Designing or selecting displays
· Designing or selecting keyboards and other input devices
· Designing workplaces for display screen users
· Supporting and training users
· Designing jobs and tasks.
Table 5 shows how we anticipated the standards being used.
4. So what went wrong?Looking back, I believe that there were a number of things which went wrong or
perhaps, more accurately, did not quite go according to plan. It has been pointed out
that hindsight has 20/20 vision. Maybe we could have anticipated more of the
problems, but I am not certain that anyone really understood the implications of what
we were doing. Certainly, until that time, much standardization work had dealt with far
more limited scopes and much more established technologies. For example, there is anentire Technical Committee which specializes in `Light gauge metal containers’
(TC52). Our sub-committee was attempting to address all the ergonomics issues
associated with interactive systems.
None the less, I believe that there were ® ve main areas where our approach could
have been better:
· It took much longer than we thought
· We and our standards were misunderstood
· We did not appreciate how political it was or would get
· We tried to be too clever
· We had too much help at times.
These points are discussed in more detail below.
4.1. It took much longer than we thoughtThe disappointment of one delegate at the meeting in Manchester has already beenmentioned but none of us appreciated just how long the process would take. One of the
1035Ergonomics user interface standards
Dow
nloa
ded
by [
Lin
naeu
s U
nive
rsity
] at
20:
48 0
5 O
ctob
er 2
014
Tab
le5.
Ho
wp
art
so
fIS
O9241
wer
ein
ten
ded
tob
euse
din
HC
Ides
ign
act
ivit
ies.
HC
Iact
ivit
yR
elev
ant
part
of
ISO
9241
Con
tents
An
aly
sin
gand
de®
nin
gsy
stem
ISO
9241-1
1:1
998
Guid
ance
on
usa
bilit
yG
uid
ance
on
usa
bilit
ysp
eci®
cati
on
,w
hic
hin
clu
des
des
crip
tio
ns
of
the
conte
xt
of
use
,th
eev
alu
ati
on
pro
cedu
res
tobe
carr
ied
ou
tand
the
crit
erio
nm
easu
res
tob
esa
tis®
edw
hen
the
usa
bilit
yo
fth
esy
stem
isto
be
evalu
ate
d.
Th
ere
are
vari
ous
situ
ati
ons
inw
hic
hu
sab
ilit
ym
ay
be
evalu
ate
d,
for
exam
ple
inp
rodu
ctdev
elop
men
t,in
pro
cure
men
to
rin
pro
du
ctce
rti®
cati
on
.T
he
com
mo
nfr
am
ewo
rkp
rese
nte
din
this
part
shou
ldb
euse
ful
inall
of
thes
esi
tuati
ons.
Des
ign
ing
use
r-sy
stem
dia
logu
esand
inte
rface
navig
ati
on
ISO
9241-1
0:1
996
Dia
logue
pri
nci
ple
sH
igh
level
ergo
no
mic
pri
nci
ple
sth
at
ap
ply
toth
edes
ign
of
dia
logu
esbet
wee
nh
um
ans
and
info
rmati
on
syst
ems.
Th
ese
incl
ude
suit
ab
ilit
yfo
rth
eta
sk,
contr
ollabil
ity
an
der
ror
tole
ran
ceam
on
gst
oth
ers.
Th
ep
rin
cip
les
are
supp
ort
edby
an
um
ber
of
scen
ari
os,
wh
ich
indic
ate
the
rela
tive
pri
ori
ties
an
dim
po
rtance
of
the
di�
eren
tp
rin
cip
les
inp
ract
ical
ap
pli
cati
ons.
ISO
9241-1
4:1
997
Men
udia
logues
Rec
om
men
dati
ons
on
men
ust
ruct
ure
,navig
ati
on
,op
tio
nse
lect
ion
and
exec
uti
on,
and
men
upre
senta
tio
n(b
yvari
ou
ste
chn
iques
incl
udin
gw
ind
ow
ing,
pan
els,
bu
tto
ns,
®el
ds,
etc.
).IS
O9241-1
5:1
998
Com
man
dd
ialo
gu
esR
eco
mm
end
ati
ons
on
com
man
dla
ngu
age
stru
ctu
reand
syn
tax,
com
man
dre
pre
-se
nta
tio
ns,
inp
ut
and
ou
tpu
tco
nsi
der
ati
ons,
feed
back
and
hel
p.
ISO
FD
IS9241-1
6:1
998
Dir
ect
man
ipula
tio
nd
ialo
gu
esR
eco
mm
end
ati
ons
on
the
man
ipu
lati
on
of
obje
cts,
and
the
des
ign
of
met
aph
ors
,o
bje
cts
and
att
ribu
tes.
Itco
ver
sth
ose
asp
ects
of
`Gra
phic
alU
ser
Inte
rface
s’w
hic
hare
dir
ectl
ym
an
ipu
late
d,
and
not
cover
edb
yoth
erpart
sof
ISO
9241.
ISO
9241-1
7:1
998
Form
-®llin
gdia
logues
Rec
om
men
dati
ons
on
form
stru
ctu
rean
dou
tput
con
sid
erati
on
s,in
put
con
sid
era-
tio
ns,
and
form
navig
ati
on
.
Des
ign
ing
or
sele
ctin
gdis
pla
ys
ISO
9241-3
:1992
Vis
ual
dis
pla
yre
quir
emen
tsD
esig
nof
scre
enhard
ware
for
o�
cevis
ual
dis
pla
yte
rmin
als
.In
ad
dit
ion
todes
ign
spec
i®ca
tion
s,th
isp
art
als
oco
nta
ins
ap
ropo
sed
use
rper
form
ance
test
as
ate
st-b
ase
dro
ute
toco
nfo
rmance
.IS
O9241-7
:1998
Req
uir
emen
tsfo
rdis
pla
ys
wit
hre
¯ec
tion
sE
rgo
no
mic
requ
irem
ents
for,
an
dd
etails
of,
met
ho
ds
of
mea
sure
men
tso
fre
¯ec
tion
sfr
om
the
surf
ace
of
dis
pla
ysc
reen
s,in
clu
din
gth
ose
surf
ace
trea
tmen
ts.
ISO
9241-8
:1997
Req
uir
emen
tsfo
rdis
pla
yed
colo
urs
The
ergo
no
mic
req
uir
emen
tsfo
rm
ult
i-co
lour
dis
pla
ys
that
sup
ple
men
tth
em
on
och
rom
ere
qu
irem
ents
inP
art
3.
(co
nti
nu
ed)
1036 T . Stewart
Dow
nloa
ded
by [
Lin
naeu
s U
nive
rsity
] at
20:
48 0
5 O
ctob
er 2
014
Table
5.
(con
tinu
ed)
HC
IA
ctiv
ity
Rel
evan
tpart
of
ISO
9241
Co
nte
nts
ISO
9241-1
2:1
998
Pre
sen
tati
on
of
info
rmati
on
Spec
i®c
soft
ware
ergo
nom
ics
issu
esin
vo
lved
inre
pre
senti
ng
an
dp
rese
nti
ng
info
rmati
on
invis
ual
form
.It
incl
ud
esgu
idan
ceo
nw
ays
of
rep
rese
nti
ng
com
ple
xin
form
ati
on
,sc
reen
layo
ut
an
dd
esig
nas
wel
las
the
use
of
win
dow
s.T
her
eis
alr
ead
ya
sub
stanti
al
bod
yo
fm
ate
rial
available
ingu
idel
ines
and
reco
mm
end
ati
ons
an
dth
isp
art
repre
sents
adis
till
ati
on
of
the
most
use
ful
an
dre
levant
ones
.
Des
ign
ing
or
sele
ctin
gk
eyb
oard
san
do
ther
inpu
td
evic
es
ISO
9241-4
:1998
Key
board
requ
irem
ents
Alp
han
um
eric
key
board
spec
i®ca
tio
nand
des
ign
(in
term
so
fth
eo
per
ati
on
of
the
key
san
dit
ser
go
no
mic
qu
aliti
es)
isco
ver
ed.
Inadd
itio
nto
des
ign
spec
i®ca
tio
ns,
this
part
als
oco
nta
ins
apro
po
sed
use
rp
erfo
rman
cete
stas
an
alt
ernati
ve
rou
teto
con
form
ance
.It
dea
lsw
ith
the
ergon
om
icasp
ects
of
the
key
bo
ard
,n
ot
the
layo
ut
wh
ich
issp
eci®
edin
ISO
9995
Key
bo
ard
layo
uts
for
text
o�
cesy
stem
s.
ISO
9241-9
:2000
Non
-key
board
inp
ut
dev
ices
Erg
ono
mic
requ
irem
ents
for
po
inti
ng
dev
ices
incl
udin
gth
em
ou
se,
track
erb
all
etc.
,w
hic
hca
nb
euse
din
con
junct
ion
wit
ha
vis
ual
dis
pla
yte
rmin
al.
Des
ign
ing
wo
rkp
lace
sfo
rd
isp
lay
scre
enuse
rsIS
O9241-5
:1998
Wo
rkst
ati
on
Erg
ono
mic
req
uir
emen
tsfo
ra
vis
uald
ispla
yte
rmin
al
wo
rkst
ati
on
that
will
allo
wth
eu
ser
toado
pt
aco
mfo
rtable
an
de�
cien
tp
ost
ure
.IS
O9241-6
:1998
Gu
idan
ceo
nth
ew
ork
envir
onm
ent
En
vir
on
men
tal
con
sider
ati
ons
(vis
ual,
aco
ust
icand
ther
mal)
.
Sup
po
rtin
gan
dtr
ain
ing
use
rsIS
O9241-1
3:1
998
Use
rguid
ance
Rec
om
men
dati
on
sfo
rth
ed
esig
nev
alu
ati
on
of
use
rgu
idan
ceatt
ribu
tes
of
soft
ware
use
rin
terf
ace
sin
clu
din
gpro
mp
ts,
feed
back
,st
atu
son
-lin
eh
elp
an
der
ror
manage-
men
t.
Des
ign
ing
job
san
dta
sks
ISO
9241-2
:1992
Gu
idan
ceo
nta
skre
qu
irem
ents
Gu
idan
ceo
nth
ed
esig
nof
dis
pla
ysc
reen
task
sb
ase
don
nea
rly
half
ace
ntu
ryof
rese
arc
han
dorg
an
izati
onal
pra
ctic
ein
soci
o-t
ech
nic
al
syst
ems.
1037Ergonomics user interface standards
Dow
nloa
ded
by [
Lin
naeu
s U
nive
rsity
] at
20:
48 0
5 O
ctob
er 2
014
reasons why the process is slow is that there is an extensive consultation period at each
stage of development with time being allowed for national member bodies to circulate
the documents to mirror committees and then to collate their comments.
Another reason is that Working Group members can spend a great deal of time
working on drafts and reaching consensus only to ® nd that the national mirrorcommittees reject their work when it comes to the o� cial vote. It is particularly
frustrating for project editors to receive extensive comments (which must be
answered) from countries who do not send experts to participate in the work. Of
course, the fact that the work is usually voluntary means that it is di� cult to get
people to agree to work quickly.
4.2. W e and our standards were misunderstoodWhile I do not accept that we have produced bad standards (at least in our committee),
our standards have been criticized for being too generous to manufacturers in some
areas and too restrictive in other areas. The `over-generous’ criticism misses the point
that most standards are setting minimum requirements and in ergonomics we must bevery cautious about setting such levels. However, there certainly are areas where being
too restrictive is a problem. Examples include the following.
(1) ISO 9241-3:1992 Ergonomics requirements for work with V DTs: V isual displayrequirements. This standard has been successful in setting a minimum standard for
display screens, which has helped purchasers and manufacturers. However, it isbiased towards Cathode Ray Tube (CRT) display technology. An alternative
method of compliance based on a performance test (which would be technology
independent) is still under development but was approved in December 1999 as a
Draft International Standard and should therefore be ® nalized in the near future.
(2) ISO 9241-9:2000 Ergonomics requirements for work with V DTs: Non keyboardinputdevices. Thisstandard hassu� ered because technologicaldevelopmentswere faster
than either ergonomics research or standards making. Although there has been an
urgent need for a standard to help usersto becon® dent in theergonomicsclaimsmadefor
newdesignsofmiceand other input devices, the lack of reliabledata forced thestandards
makers to slow down or run the risk of prohibiting newer, even better solutions.
The biggest area of misunderstanding is that some people seem surprised todiscover that user interface standards not only do not solve all the problems in user
interface design, but also they do not even address some of the most di� cult parts of
design. I am really not sure where this misunderstanding arose. Even though we, in
the standards community, believe that standards are part of the solution, I do not
know anyone who believes that they are the whole story or thinks that they shouldbe. Elizabeth Buie (1999) has published an excellent review of such problems and
explains how standards ® t into the overall picture.
4.3. W e did not appreciate how political it was or would getAlthough ergonomics standards are generally concerned with such mundanetopics as keyboard design or menu structures, they none the less generate
considerable emotion amongst standards makers. Sometimes this is because the
resulting standard could have a major impact on product sales or legal
liabilities. At other times the reason for the passion is less clear. None the less,
the strong feelings have resulted in painful experiences in the process of
standardization, especially for me as committee chairman. These have included
1038 T . Stewart
Dow
nloa
ded
by [
Lin
naeu
s U
nive
rsity
] at
20:
48 0
5 O
ctob
er 2
014
the following.
(1) Undue influence of major players. Large multinational companies can try to
exert undue influence by dominating national committees. Although draft
standards are usually publicly available from national standards bodies, theyare not widely publicized. This means that it is relatively easy for well informed
large companies to provide sufficient experts at the national level to ensure that
they can virtually dictate the final vote and comments from a country.
(2) `Horse trading’ and bargaining to achieve agreement. End users’ requirements
can be compromised as part of `horse trading’ between conflicting viewpoints.In the interests of reaching agreement, delegates may resort to making political
trade-offs largely independent of the technical merits of the issue.
(3) Uncritical support for favourite ideas. National pride can lead to uncritical
support for a particular approach or methodology. In theory, participants in
Working Group meetings are experts nominated by member bodies in the
different countries. They are not there to represent a national viewpoint but aresupposed to act as individuals. However, as one disillusioned expert explained
to me s̀ometimes the loudest noise at a Working Group meeting is the grinding
of axes’ .
4.4. W e tried to be too cleverOne of the criticisms we face as ergonomics and human factors specialists is that we
generally spend too much time talking to ourselves. I am not referring to some
abnormal mental state of delusion but rather the tendency amongst all experts to be
more interested in the views of their fellows than in addressing the wider public. The
same criticism can be levelled at standards makers. Indeed, in ISO, the formal rulesand procedures for operating seem to encourage an elitist atmosphere with standards
written for standards enthusiasts. ISO has recognized this and is attempting to make
the process more customer focused but such changes take time. Within our
committees, these procedures and rules have reinforced our elitist tendencies and
sometimes resulted in standards that leave much to be desired in terms of brevity,
clarity and usability. There are three contributory factors:
(1) The use of stilted language and boring formats. The unfriendliness of the
language is illustrated by the fact that although the organization is known by
the acronym ISO, its full English title is the International Organization for
Standardization. The language and style are governed by a set of Directives andthese encourage a wordy and impersonal style.
(2) Problems with translation and the use of `near English’ . There are three official
languages in ISOÐ English, F rench and Russian. In practice, much of the work
is conducted in English, often by non-native speakers. As someone who only
speaks English, I have the utmost respect for those who can work in more thanone language. However, the result of this is that the English used in standards is
often not quite correctÐ it is `near English’ . The words are usually correct but
their combination often makes the exact meaning unclear. These problems are
exacerbated when the text is translated.
(3) Confusions between requirements and recommendations. In ISO standards, there
are usually some parts which specify what has to be done to conform to thestandard. These are indicated by the use of the word s̀hall’ . However, in
1039Ergonomics user interface standards
Dow
nloa
ded
by [
Lin
naeu
s U
nive
rsity
] at
20:
48 0
5 O
ctob
er 2
014
ergonomics standards, we often want to make recommendations as well. These
are indicated by the use of the word s̀hould’ . Such subtleties are often lost on
readers of standards, especially those in different countries. For example, in the
Nordic countries, they follow recommendations (shoulds) as well as require-
ments (shalls), so the distinction is diminished. In the USA, they tend to ignorethe s̀houlds’ and only act on the s̀halls’ .
4.5. W e had too much help at timesThis might sound like an unlikely problem but given the long time-scale mentioned
above it can be a signi® cant factor in slowing down the process. The reason is thatmany experts are only supported by their organizations for a relatively short time
and are then replaced by other experts. Every time a new expert joins the Working
Group, there is a tendency to spend a lot of time explaining the history and to some
extent starting the process again. Similarly, each expert feels obliged to make an
impact and suggest some enhancement or change in the standard under
development. Since the membership of Working Groups can change at virtuallyevery meeting (which are usually 3 or 4 months apart), it is not uncommon for long-
standing members to ® nd themselves reinstating material which was deleted two or
three meetings previously (as a result of a particularly forceful individual).
5. It was not all badAs I mentioned at the beginning of this paper, neither my colleagues in
standardization nor I would spend so much time and e� ort if we did not believe
the results would be worthwhile. Looking back, some things really worked well and
in mitigation of the criticisms, I would argue the following:
· Slower is not necessarily worse
· Structure and formality can be a help as well as a hindrance
· Standards do not have to be unduly restrictive
· The bene® ts do not just come from the standards themselves
· Being international makes it all worthwhile.
· These points are argued in more detail below.
5.1. Slower is not necessarily worseStandards making is painfully slow. I am not suggesting that this is good, especially
in such a fast moving area as user interface design. However, there are some bene® ts
that come directly from the pace of the process, in addition to the widespreadconsultation which I have already mentioned.
One bene® t is that when the technology is moving quicker than the standards
makers can react, it does make it clear that certain types of standards may be
premature. For example, ISO 9241-14:1997 Menu dialogues was originally proposed
when character-based menu-driven systems were a popular style of dialogue design.Its development was delayed considerably for all manner of reasons (many beyond
our control). However, these delays meant that the ® nal standard was relevant to
pull down and pop-up menus which had not even been considered when the standard
was ® rst proposed.
Another bene® t is that during the development process, those who may be
a� ected have the opportunity to prepare for the standard. Thus by the time ISO9241-3:1992 Visual display requirements was published, many manufacturers were
1040 T . Stewart
Dow
nloa
ded
by [
Lin
naeu
s U
nive
rsity
] at
20:
48 0
5 O
ctob
er 2
014
able to claim that they already produced monitors that met the standard. They had
not been in that position when the standard was ® rst proposed and although they
might like to argue that they would have been improving the design of their displays
anyway, I am not convinced that this is entirely true. Certainly the standards
provided a clear target for both demanding consumers and quality manufacturers.
5.2. Structure and formality can be a help as well as a hindranceOne of the bene® ts of standards is that they do represent a rather simpli® ed and
structured view of the world. There is also a degree (sometime excessive) of discipline
in what a standard can contain and how certain topics can be addressed.Manufacturers (and ergonomists) frequently make wildly di� erent claims about
what represents good ergonomics. This is a major weakness for our users who may
conclude that all claims are equally valid and there is no sound basis for any of it.
Standards force a consensus and therefore have real authority in the minds of our
users. Achieving consensus requires compromises, but then so does life.
The formality of the standards mean that they are suitable for inclusion in formalprocurement processes and for demonstrating best practice. In the UK at least, parts
of ISO 9241 may be used by suppliers to convince their customers that visual display
screen equipment and its accessories meet good ergonomics practice. Of course, they
can also be `abused’ in this way with over-eager salesmen misrepresenting the legal
status of standards but that is hardly the fault of the standards makers.
5.3. Standards do not have to be unduly restrictiveI have already described the problem that was experienced during the development
of ISO 9241 caused by the technology being developed faster than we could reach
agreement on the standards. I have also explained that ISO 9241-3:1992 now has anAmendment which o� ers a method of complying with design requirements through
user testing which is therefore relatively technology independent.
However, standards that specify how products should be made are not the only
types of ergonomics standards which are possible. In late 1992, we started work on a
process standard ISO 13407:1999 Human-centred design processes for interactive
systems, which aims to provide guidance for project managers to help them to followa human-centred design process. By undertaking the activities and following the
principles described in the standard, managers can be con® dent that the resulting
systems will be usable and will work well for their users.
The standard describes four principles of human-centred design:
(1) active involvement of users (or those who speak for them);
(2) appropriate allocation of function (making sure human skill is used properly);
(3) iteration of design solutions (allowing time for iteration in project planning);
(4) multi-disciplinary design (but beware of large design teams);
and four key human-centred design activities:
(1) understand and specify the context of use (make it explicitÐ do not assume that
it is obvious);
(2) specify user and organizational requirements (note that there will be a variety ofdifferent viewpoints and individual perspectives);
1041Ergonomics user interface standards
Dow
nloa
ded
by [
Lin
naeu
s U
nive
rsity
] at
20:
48 0
5 O
ctob
er 2
014
(3) produce design solutions (note plural, multiple designs encourage creativity);
and
(4) evaluate designs against requirements (involves real user testing not just
convincing demonstrations).
In order to claim conformance, the standard requires that the procedures used,
the information collected and the use made of results are speci® ed (a checklist is
provided as an annex to help). We have developed this approach to conformance
in a number of parts of ISO 9241 since so many ergonomics recommendations
are context-speci® c. Thus there is often only one s̀hall’ in these standards whichgenerally prescribes what kind of evidence is required to convince another party
that the relevant recommendations in the standard have been identi® ed and
followed.
There has already been considerable international interest in ISO 13407 and we
believe that there will be increasing demands from large customers for evidence that
their system suppliers follow this kind of process.
5.4. The bene® ts do not just come from the standards themselvesThere are several ways in which ergonomics standardization activit ies can add value
to user interface design apart from the standards themselves, which are the end
results of the process.I have already mentioned that some of those manufacturers who recruited
ergonomics and human factors people to defend themselves against standards (my
personal and probably somewhat biased view) found that these individuals could
add value to the design of user interfaces. Although many of these experts have now
joined the ranks of independent consultants, I believe that they had a signi® cantimpact in terms of raising awareness about the importance of usability.
In 1997, the US National Institute of Standards and Technology (NIST) initiated
a project (Industry USability Reporting, IUSR) to increase the visibility of software
usability. They were helped in this endeavour by prominent suppliers of software and
representatives from large consumer organizations. One of the key goals was to
develop a common usability reporting format (Common Industry Format, CIF).This is currently being piloted. Although the e� ort is independent of other
standardization bodies or activities, the CIF has been developed to be consistent
with ISO 9241 and ISO 13407 and is viewed by the IUSR team as `an
implementation of that ISO work’ . I believe this activity in itself will have a major
impact on software usability (http://www.nist.gov/iusr).In the hardware arena, many people are aware of the TCO 99 sticker which
appears on computer monitors and understand that it is an indication of ergonomic
and environmental quality. What they may not know is that TCO is the Swedish
Confederation of White Collar Trades Unions and that ISO 9241 was used as a
major inspiration for its original speci® cation. They publish information in Englishand details are available on their website at http://www.tco.se/eng/index.htm.
5.5. Being international makes it all worthwhileF inally, I am a strong believer in taking a global perspective on ergonomics (and
indeed on many other issues). Although there are national and regional di� erences in
populations, the world is becoming a single market with the major suppliers taking aglobal perspective.
1042 T . Stewart
Dow
nloa
ded
by [
Lin
naeu
s U
nive
rsity
] at
20:
48 0
5 O
ctob
er 2
014
Variations in national standards and requirements not only increase costs and
complexity, but they also tend to compromise individual choice. Making standards
international is one way of ensuring that they have impact and can help to improve
the ergonomics quality of products for everyone. That has to be a worthwhile
objective. Table 6 shows the member countries of ISO/TC159/SC4.
6. Next steps
Having taken more than 17 years to develop ISO 9241, you might be forgiven for
believing that we would want a rest . In fact, what the experience has taught us is
that there is a great deal that we would have done di� erently all those years ago,had we known then what we know now. In ISO/TC 159/SC4, we have recently
been trying to apply customer-centred methods to our own work. Recognizing
how long it takes to develop standards and that we do not have unlimited
resources, we have been planning our strategy and we have come to some
tentative conclusions for our ® ve-year plan. We have identi® ed a number of key
standards that we would like to have in place by that time. One major di� erencefrom ISO 9241 is that we do not intend to restrict ourselves to o� ce tasks nor
indeed do we believe that we should be developing a single family of standards
with a common scope or structure.
However, we have identi® ed seven areas where we believe that we can identify a
need for standards and a clear population of potential readers of the standardsdocuments.
Although discussions are still at a very early stage, we envisage standards being
developed (or existing standards being updated) to support the following.
· Visual displaysÐ design and assessment tools for manufacturers, designers,Original Equipment Manufacturers (OEM), testers, evaluators and buyers
· Physical input devicesÐ design and assessment tools for manufacturers,
testers and selection combination tools for buyers
· Voice/speech interface design requirements for application developers
· Design process guidance for project managers and designers
· Workplace customization use and selection for system designers inorganizations
· Interaction, dialogue, navigation and presentation requirements and
guidance for applications designers
· Evaluation, metrics and measurement criteria guidance for end users and
managers and test methods for usability experts.
Although I believe that standards are an important tool for the ergonomist, many
people ® nd them di� cult to understand and use. The best way to really understand
what is going on in standards is to get involved. This will give you advance warning
Table 6. Members of ISO/TC159/SC4 Ergonomics of Human-System Interaction.
`P’ members(Participants)
Austria, Belgium, Canada, Czech Republic, China, Denmark,F inland, F rance, Germany, Ireland, Italy, Japan, Korea, Netherlands,Norway, Poland, Slovakia, Spain, Sweden, Thailand, UK and USA
`O’ members(Observers)
Australia, Hungary, Mexico, Romania and Tanzania
1043Ergonomics user interface standards
Dow
nloa
ded
by [
Lin
naeu
s U
nive
rsity
] at
20:
48 0
5 O
ctob
er 2
014
of future standards, the opportunity to in¯ uence the content of standards and an
understanding of the context in which they have been developed. You will then ® nd
it much easier to make e� ective use of standards. If you would like more information
on ISO, you will ® nd their website an excellent starting point with links to national
and other standards sites (http://www.iso.ch).
Acknowledgements
I would like to thank my many colleagues from around the world with whom I have
had the pleasure of working to develop standards over the past 17 years.
ReferencesBU IE, E. 1999, HCI standards: A mixed blessing, Interactions, 6 (2), 36 ±42.STEWART, T. 1998, Ergonomics standardsÐ the good, the bad and the ugly, in M. A. Hanson
(ed.), Contemporary Ergonomics 1998 (London: Taylor & Francis), 3 ±7.STEWART, T. 1999, Experiences (painful and good) developing HCI standards, Proceedings of
Interact 99, Volume II, Edinburgh, 30th August to 3rd September (Swindon: BritishComputer Society), 196 ±200.
1044 Ergonomics user interface standards
Dow
nloa
ded
by [
Lin
naeu
s U
nive
rsity
] at
20:
48 0
5 O
ctob
er 2
014