Bendzioch, S en; Hin ichsen, S en
A icle — Published Ve sion
Po en ials o an in o ma ional assembly assis ance
sys em o pe sons wi h cogni i e disabili ies—Resul s o
alabo a o y s udy
Zei sch i ü A bei swissenscha
P o ided in Coope a ion wi h:
Sp inge Na u e
Sugges ed Ci a ion: Bendzioch, S en; Hin ichsen, S en (2024) : Po en ials o an in o ma ional
assembly assis ance sys em o pe sons wi h cogni i e disabili ies—Resul s o alabo a o y s udy,
Zei sch i ü A bei swissenscha , ISSN 2366-4681, Sp inge , Be lin, Heidelbe g, Vol. 78, Iss. 2, pp.
240-253,
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Zei sch i ü A bei swissenscha (2024) 78:240–253
Po en ials o an in o ma ional assembly assis ance sys em o pe sons
wi h cogni i e disabili ies—Resul s o a labo a o y s udy
S en Bendzioch1·S enHin ichsen
1
Accep ed: 13 Ma ch 2024 / Published online: 11 Ap il 2024
© The Au ho (s) 2024
Abs ac
In Ge many, indi iduals unable o no ye able o e u n o he gene al labo ma ke due o disabili ies a e employed in
shel e ed wo kshops which a e called W bM (“We ks ä en ü behinde e Menschen”). These o ganiza ions a e equi ed
o ea n he wages o he a o emen ioned g oup o people by o e ing ma ke se ices. These se ices include, in pa icula ,
assembly ac i i ies. Howe e , W bM ace he challenge ha cus ome o de s end o become mo e complex, especially
as a esul o an inc eased numbe o p oduc a ian s. This de elopmen no only has an impac on he wo k in W bM,
bu also makes i much mo e di icul o achie e he desi ed inclusion o people wi h disabili ies in he gene al labo
ma ke . Bea ing his in mind, he esea ch ques ion add essed in his a icle can be s a ed as such: How a can he use
o an in o ma ional assis ance sys em compensa e o pe o mance de ici s o people wi h disabili ies in he con ex o
assembly? The esul s o he conduc ed labo a o y s udy show ha he implemen a ion o an assis ance sys em can help
o educe exis ing ba ie s and challenges esul ing om he misma ch be ween equi emen s o he gene al labo ma ke
and he pe o mance cha ac e is ics o people wi h cogni i e impai men s.
P ac ical Rele ance: Fo people wi h disabili ies, he use o assis ance sys ems opens up new oppo uni ies o pa ic-
ipa ion in he gene al labo ma ke and hus makes an impo an con ibu ion o implemen ing he equi emen s o he
“Bundes eilhabegese z” (a law o s eng hen pa icipa ion o people wi h disabili ies in Ge many).
Keywo ds In o ma ional Assis ance Sys em · People wi h Disabili ies · Manual Assembly · Image P ocessing Sys em ·
Labo a o y S udy
P o . D .-Ing. S en Hin ichsen
s en.hin i[email p o ec ed]
1Indus ial Enginee ing Lab, Os wes alen-Lippe Uni e si y o
Applied Sciences and A s, Campusallee 12, 32657 Lemgo,
Ge many
K
Zei sch i ü A bei swissenscha (2024) 78:240–253 241
Po enziale eines in o ma o ischen Mon ageassis enzsys ems ü Pe sonen mi kogni i en
Un e s ü zungsbeda en – E gebnisse eine Labo s udie
Zusammen assung
In Deu schland we den Pe sonen, die au g und on Beein äch igungen nich bzw. noch nich wiede au dem allgemeinen
A bei sma k ä ig sein können, in eine „We ks a ü behinde e Menschen (W bM)“ beschä ig . Diese Ein ich ungen
müssen die A bei sen gel e ü den genann en Pe sonenk eis du ch am Ma k angebo ene Leis ungen selbs e wi scha en.
Zu diesen Leis ungen zählen o allem Mon age ä igkei en. Alle dings s ehen W bM o de He aus o de ung, dass Kun-
denau äge insbesonde e in olge eine ges iegenen Va ian en iel al endenziell komplexe we den. Diese En wicklung
wi k sich nich nu au die A bei in den We ks ä en aus, sonde n ha auch zu Folge, dass die anges eb e Inklusion on
Pe sonen mi Un e s ü zungsbeda en in den allgemeinen A bei sma k deu lich e schwe wi d. Vo diesem Hin e g und
wi d in dem Bei ag de Fo schungs age nachgegangen, inwiewei de Einsa z eines in o ma o ischen Assis enzsys ems
Leis ungsde izi e on Pe sonen mi Un e s ü zungsbeda en im Kon ex de Mon age ausgleichen kann. Die E gebnisse de
du chge üh en Labo s udie zeigen, dass die Ein üh ung eines Assis enzsys ems dazu bei agen kann, bes ehende Ba ie en,
die sich aus de Inkong uenz zwischen den An o de ungen des allgemeinen A bei sma k es und den Leis ungsme kmalen
on Pe sonen mi kogni i en Beein äch igungen e geben, abzubauen.
P ak ische Rele anz: De Einsa z on in o ma o ischen Assis enzsys emen kann Pe sonen mi Un e s ü zungsbeda en eine
Teilhabe am A bei sleben e möglichen und leis e dami einen wich igen Bei ag zu Umse zung des Bundes eilhabegese -
zes.
Schlüsselwö e In o ma o isches Assis enzsys em · Pe sonen mi Un e s ü zungsbeda en · Manuelle Mon age ·
Bild e a bei ungseinhei · Labo s udie
1In oduc ion
In Ge many, indi iduals unable o no ye able o e u n o
he gene al labo ma ke a e employed in shel e ed wo k-
shops (We ks ä en ü behinde e Menschen (W bM), in
li e al ansla ion “wo kshops o people wi h disabili ies”).
Thei pu pose is o enable in eg a ion and pa icipa ion in
wo king li e and o p omo e he ansi ion o sui able people
o he gene al labo ma ke ia app op ia e measu es (§ 219
SGB IX). In o al, he e a e o e 700 main wo kshops in
Ge many wi h mo e han 3000 acili ies, employing a ound
310,000 people wi h disabili ies (Be g e al. 2023). Im-
pai men s a e di ided in o physical, men al, and cogni i e
impai men s, wi h people wi h cogni i e pe o mance im-
pai men s being p ima ily employed in W bM—75.3% o
he wo k o ce in 2022 (Be g e al. 2023). Al hough hese
wo kshops a e p edominan ly inanced by he s a e, hey
mus gene a e he wages o hose employed in he wo king
a ea hemsel es by o e ing se ices on he ma ke (Sec ion
221 (2) SGB IX). Many o he se ices o e ed a e based
p ima ily on simple assembly and packing ac i i ies o
he indus ial en e p ises loca ed in hei espec i e egion
(Doose 2009). The asks on which hese ac i i ies a e based
a e o en cha ac e ized by la ge ba ches and hus high epe-
i ion equencies as well as low wo k con en , so ha e en
people wi h cogni i e impai men s can lea n hese asks and
de elop a ou ine. Wo kshops, howe e , a e aced wi h he
challenge ha he numbe o a ian s o hei cus ome s’
p oduc s is in many cases inc easing and ha mo e and
mo e quali y equi emen s mus be aken in o accoun . Case
s udies in he “SInnAssis ” p ojec ha e shown ha people
employed in W bM a e some imes unable o ake hese in-
c eased equi emen s in o accoun , esul ing in assembly e -
o s and complain s om W bM cus ome s. In addi ion, an
inc ease in he complexi y o assembly and packing asks in
indus ial en e p ises nega i ely impac s he in ended goal
o inclusion o people wi h cogni i e impai men s in he
gene al labo ma ke , meaning ha ans e s om W BM
o “no mal” companies a e o en unsuccess ul. The cu en
ansi ion a e in Ge many is only a ound 0.16% pe yea ,
i.e., e y ew people wi h disabili ies succeed in making he
swi ch (De ma e al. 2008).
2 S a e o esea ch
Employees in mul i- a ian assembly ha e o abso b and
p ocess la ge amoun s o in o ma ion by con inuously mak-
ing decisions abou he componen s o be assembled, and
he ools o wo king me hods o be used. The sha e o in-
o ma ional wo k in assembly ends o inc ease as mo e
and mo e p oduc s a e con igu ed acco ding o cus ome
equi emen s and supplemen a y unc ions and hus com-
ponen s a e in eg a ed in o p oduc s. Whe eas manual as-
sembly was o a long ime conside ed p ima ily as an en-
e ge ic wo k, in he p esen and u u e, he in o ma ional
opics o assembly a e o be emphasized. The design o
manual assembly sys ems is he e o e in he mean ime o
K
242 Zei sch i ü A bei swissenscha (2024) 78:240–253
a la ge ex en also a ield o cogni i e e gonomics (Holl-
nagel 1997; Bläsing e al. 2021).
Empi ical s udies poin o mul iple de ici s in he in-
o ma ional design o manual assembly sys ems (Claeys
e al. 2015). These incompa ibili ies be ween he in o ma-
ion demand o he employee and he in o ma ion sup-
ply in he wo k sys em lead, o example, o ask in e -
up ions, sea ch p ocesses o consul a ions wi h supe io s,
colleagues o designing enginee s, which means ha he
sha e o con ingency allowances in he p oduc ion imes
inc eases (Hin ichsen and Bendzioch 2019). Incompa ibili-
ies canno usually be a oided al oge he , only minimized.
Thus, acco ding o he complexi y-compa ibili y pa adigm,
an inc ease in complexi y in a wo k sys em leads o a de-
c ease in he e ec i eness po en ial o e gonomic measu es
(Ka wowski 2005). Typical incompa ibili ies be ween in-
o ma ion demand and supply a e e e ed o as “de ici s”
(S asse 2021) o “gaps” (Hin ichsen e al. 2022). These
ypical incompa ibili ies can be highligh ed using a model
o human in o ma ion p ocessing (e.g., Schlick e al. 2018;
see Fig. 1). The i s incompa ibili y shown in he model
may occu when he assemble lacks in o ma ion (“missing
da a”) o pe o m he nex assembly s ep (Gap 1). I ’s also
possible ha he p o ided assembly ins uc ions con ain e -
o s (“w ong da a”—Gap 2). Bu e en i all he equi ed
da a o in o ma ion is a ailable and co ec , he employee
may no be awa e o he in o ma ion because i is, o exam-
ple, included in a complex design d awing and o e looked
(“no di ec pe cep ion o he da a”—Gap 3). I he employee
pe cei es he equi ed da a, he e may s ill be he p oblem
o misin e p e ing o complica ed and ime-consuming de-
coding o he da a (Gap 4). And e en i he da a p o ided
a e in e p e ed co ec ly, dis ac ions o ina en ion can lead
o inco ec ac ions (“ ou ine e o ”—Gap 5). I he e is no
eedback om he sys em (Gap 6), he e o may no be
co ec ed o unce ain ies may a ise ha lead o addi ional
ac i i ies (e.g., asking colleagues). In addi ion, indi idual
Fig. 1 Gap model o in o ma ion p ocessing in manual assembly (Hin-
ichsen e al. 2022, modi ied)
Abb. 1 Lückenmodell de In o ma ions e a bei ung in de manuellen
Mon age (Hin ichsen e al. 2022, modi izie )
gaps, o example Gap 4, a ise om o ge ing in o ma ion
(Gap 7) o in e indi idual di e ences in expe ience (Gap 8).
E gonomically p epa ed in o ma ion, in conjunc ion
wi h in o ma ional assis ance sys ems, can help o mini-
mize o close indi idual gaps. In his espec , assis ance
sys ems aim o p o ide he igh in o ma ion a he igh
ime and in he desi ed o m (Claeys e al. 2015), so ha
i can be mo e easily abso bed andp ocessedby heem-
ployee. Fo his pu pose, assis ance sys ems a e con igu ed
in acco dance wi h ope a ional and pe sonnel equi emen s.
Key aspec s ha allow modi ica ion include he equi ed
ha dwa e componen s, he use in e ace, and he connec-
ion o o he IT sys ems (Hold e al. 2017). This way,
o example, in o ma ion can be ou pu s ep by s ep ia
a sc een. In addi ion, assis ance sys ems o e he possibili y
o using a ious senso s, such as a ision senso , o p o ide
eedback on whe he indi idual picking o assembly s eps
ha e been ca ied ou in acco dance wi h equi emen s.
Assis ance sys ems a e desc ibed as adap i e i hey can
be ailo ed o selec ed cha ac e is ics o employees (e.g.,
changing he on size o compensa e o a use ’s isual
impai men ; ex en o suppo p o ided by he assis ance
sys em depending on he use ’s expe ience).
In o ma ional assis ance sys ems hus o e a non-negli-
gible po en ial o u he esol e he disc epancy be ween
he equi emen s o he gene al labo ma ke and he pe o -
mance cha ac e is ics o people wi h cogni i e impai men s.
A o al o six s udies could be iden i ied ha explici ly deal
wi h he po en ial capabili ies o in o ma ional assis ance
sys ems ega ding people wi h disabili ies (Table 1). The
objec o hese s udies we e di e en display and ou pu
modali ies o in o ma ional assis ance sys ems in compa -
ison o a con ol medium. T ial con en included assem-
bling Lego®assemblies ( wo o six ials), cu ing pa s
o a jewel y box, inse ing pa s o a sc ew clamp in o
a machine, assembling i e mul i-ou le powe s ips, and
moun ing h ee me al ings on a me al od. The o al e-
sul s a e o be e alua ed as posi i e. Fo example, using
an in o ma ional assis ance sys em p edominan ly leads o
sho e execu ion imes and ewe e o s o be e wo k e-
sul s (Funk e al. 2015a, b; Aksu e al. 2019;Ma ke al.
2021; Bendzioch and Hin ichsen 2023). Howe e , he sig-
ni icance o hese esul s is es ic ed o limi ed by he ac
ha he sample size is some imes oo small and/o he sub-
jec s in he expe imen al and con ol g oups a e iden ical
(sequence e ec s). Fu he mo e, i can be seen om Table 1
ha in some s udies he compa ison medium is no speci-
ied in de ail, which makes i di icul o in e p e he esul s.
Simila ly, only wo s udies conside an indus ial assembly
ask (Ma k e al. 2021; Bendzioch and Hin ichsen 2023),
making i di icul o ans e he o he indings o manual
assembly. Al hough an indus ial assembly is also used in
he s udy by Funk e al. (2015a), he ac i i y is no a con-
K
Zei sch i ü A bei swissenscha (2024) 78:240–253 243
Table 1 S udies on he applica ion po en ials o in o ma ion-based assembly assis ance sys ems o people wi h disabili ies
Tab. 1 S udien zu den Einsa zpo enzialen on in o ma o ischen Mon ageassis enzsys emen ü Pe sonen mi Un e s ü zungsbeda
Au ho Assembly Task Assis ance Medium Re e ence
Medium
Pa icipan s (G oups)
Aksu e al. (2019) Cu ing p ocess o a jewel y
box
In o ma ion on a no ebook No speci ied n=5
(2 g oups o 5 pe sons)
Bendzioch and Hin-
ichsen (2023)
Moun ing i e socke s ips Moni o wi h an image p o-
cessing uni
Pape -based
ins uc ion
n=20
(2 g oups o 10 pe sons)
Funk e al. (2015a) Inse i e componen s o
a sc ew clamp in o a machine
P ojec o o displaying pic-
u es, ideos, and con ou s
Ve bal ins uc-
ion
n=64
(4 g oups o 16 pe sons)
Funk e al. (2015b) Fi e Lego®assemblies
wi h6 o48pa s
P ojec o wi h image p ocess-
ing uni
In o ma ion on
a moni o
n=15
(2 g oups)
Ko n e al. (2013)Lego
®assembly wi h 8 pa s P ojec o and a moni o wi h
a gami ica ion app oach
In o ma ion on
a moni o
n=60
(3 g oups o 20 pe sons)
Ma k e al. (2021) Moun ing h ee me al ings on
a me al od
Combina ion o se e al assis-
ance sys ems
No speci ied n=7
(2 g oups o 7 pe sons)
en ional assembly ope a ion, bu me ely he inse ion o
componen s in o a machine. In addi ion, i should be no ed
ha a ian di e si y, i.e., swi ching be ween di e en asks,
has only been conside ed in wo s udies (Funk e al. 2015b;
Bendzioch and Hin ichsen 2023). Howe e , gi en he end
ha he complexi y o assembly asks is inc easing, he
cogni i e ansi ion om one ask o he nex should be
unde s ood as an essen ial skill o wo k equi emen .
O e all, he analysis o exis ing s udies clea ly shows
ha he e is a need o u he esea ch o be e speci y he
po en ial use o in o ma ion-based assis ance sys ems o
people wi h cogni i e impai men s in mul i- a ian assem-
bly. A ques ion ha needs o be add essed in pa icula is he
ex en o which such a sys em is sui able o compensa ing
pe o mance de ici s when compa ed wi h a con ol g oup
o people wi hou cogni i e pe o mance impai men s, in
o de o gi e people wi h such an impai men be e access
o he gene al labo ma ke in he u u e.
3Objec i e
Exis ing mechanisms o p ejudice o s e eo ypes abou he
pe o mance o people wi h impai men s—di ec o indi-
ec disc imina ion—make he ansi ion o he gene al la-
bo ma ke mo e di icul (Ka do e al. 2013). Wi h his
in mind, he exis ing esea ch design o he p e iously
men ioned s udy by Bendzioch and Hin ichsen (2023)is
ex ended o include ano he g oup o people, indi iduals
wi hou cogni i e pe o mance limi a ions, o u he ex-
plo e he e ec s o an in o ma ional assembly assis ance
sys em. The esea ch ques ion o be speci ically add essed
is: To wha ex en can he use o an in o ma ional assis ance
sys em compensa e o pe o mance de ici s o indi iduals
wi h cogni i e impai men s ( ela i e o a compa ison g oup
o people wi hou cogni i e pe o mance impai men s) in
he con ex o mul i- a ian assembly? The s udy hus ad-
d esses he esea ch gap ou lined in he S a e o Resea ch
and is in ended o p o ide in o ma ion on imp o ed inclu-
sion h ough compa ison wi h a con ol g oup (indi iduals
wi hou cogni i e pe o mance impai men s).
4 Design o expe imen and me hodology
4.1 Resea ch design
4.1.1 Suppo sys ems
In he expe imen al s udy, wo ypes o assis ance a e used:
An assis ance sys em om he RICOH company and a pa-
pe -based assembly ins uc ion—which is s ill common in
many companies (Banna 2014). The assembly assis ance
sys em—RICOH SC-10A (H)—is an image p ocessing sys-
em, ha o e s a special ea u e by which he employee no
only ecei es eedback on he e o - ee o aul y execu ion
o each assembly s ep bu is also shown ins uc ions on how
o execu e he s ep. Assembly ins uc ions can be c ea ed
qui e easily (wi hou p og amming) ia so wa e. A sc een
se es as he ou pu de ice o all in o ma ion.
The in o ma ion ele an o assembly is p epa ed wi h
he same con en and scope o in o ma ion o bo h ypes
o suppo (assis ance sys em and pape manual). These a e
based on a s ep-by-s ep assembly ins uc ion, which con-
ains in o ma ion on how o ca y ou indi idual ope a ions
and on he ools and ma e ials equi ed o each ope a ion
(see Fig. 2). Conside ing ha assembly ins uc ions o en
ha e de ici s in p ac ice (Hin ichsen and Bendzioch 2019),
special a en ion was paid o making he s ep-by-s ep as-
sembly ins uc ions as use -cen e ed as possible by in ol -
ing employees om a wo kshop o people wi h disabili-
ies in he design. In he ins uc ion, o example, ma e ial
e ie al is aided by highligh ing he ele an con aine po-
K
244 Zei sch i ü A bei swissenscha (2024) 78:240–253
Pape Based Ins uc ion Assis ance Sys em
S ep 8 o 12
Fig. 2 Assis ance sys ems used in esea ch design
Abb. 2 Eingese z e Un e s ü zungssys eme im Fo schungsdesign
si ions in a ue- o-scale illus a ion o he ma e ial supply
(see Fig. 2).
As can be seen om Fig. 2, he in o ma ion ele an o
assembly is p o ided in he same o m and o he same ex-
en o bo h media, wi h he excep ion ha in he case o
he assis ance sys em, addi ional eedback is ou pu ia he
igh side o he sc een ega ding he e o - ee o inco ec
execu ion o an assembly s ep. This eedback akes he o m
o a li e image eco ded by he image p ocessing uni , on o
which he p e iously de ined inspec ion ea u es a e supe -
imposed. Only when all de ined inspec ion cha ac e is ics
ma ch he s o ed e e ence image will in o ma ion on he
nex assembly s ep be displayed on he sc een. This ensu es
ha , a he ime o es ing, he inspec ion cha ac e is ics de-
ined o an assembly s ep, and wi h ha he espec i e
assembly ope a ions, ha e been ca ied ou wi hou e o .
4.1.2 Assembly ask
In o de o ensu e applicabili y o he s udy esul s o in-
dus ial p ac ice, he p esen s udy uses a ious p oduc s
om one manu ac u e o mul i- a ian powe s ips. These
p oduc s a e assembled in he labo a o y bu using o igi-
nal pa s and ools. The objec o he s udy a e i e di e -
en a ian s o a mul i-ou le powe s ip (see Fig. 3). To
simula e a mul i- a ian o cus ome -speci ic assembly, he
p oduc s di e in hei colo design, making i di icul o
Fig. 3 Assemblies acco ding o
he s udy design (Bendzioch and
Hin ichsen 2023, modi ied)
Abb. 3 Baug uppen im Fo -
schungsdesign (Bendzioch und
Hin ichsen 2023, modi izie )
P oduc I
P oduc II
P oduc III
P oduc IV
P oduc V
he subjec s o de elop ou ines and equi ing a “cogni i e
adjus men ” om p oduc o p oduc .
The o de shown in Fig. 3is binding o all es pa -
icipan s. This o de was de e mined a andom. A o al o
18 indi idual pa s a e equi ed pe powe s ip assembly,
wi h he es subjec s ha ing o dis inguish be ween 13 di -
e en pa s in he wo k sys em. In addi ion, he assembly
ask is no able o he ac ha e y di e en e o s (e.g.,
inco ec posi ioning o mixing up o indi idual pa s) can
occu du ing i s execu ion.
4.1.3 Expe imen al se up
The expe imen al p ocedu e is ca ied ou a a s anding
wo ks a ion sold by he company RK Rose+K iege . The
wo king su ace o he assembly able has dimensions
1210× 540mm. The minimum wo king heigh is 933mm.
To ensu e e gonomic pos u e, he wo ks a ion is heigh
adjus able—400mm li ing columns. Simila ly, he wo k-
s a ion ea u es wo sepa able elemen s, he assembly able
and he ma e ial supply ack (see Fig. 4). On he wo k
su ace o he assembly able, he e is a wooden assembly
ix u e, designed o simpli y handling and joining indi-
idual pa s. The indi idual pa s a e supplied ia g ab
con aine s a anged on wo le els. To be able o clea ly
dis inguish he g ab con aine s and he pa s s o ed in hem
om each o he , a label wi h he ma e ial numbe and pa
designa ion is a ached o each con aine .
Fo he assembly o he mul i-ou le powe s ips,
a o que-con olled sc ewd i e suspended om a ool
balance is a ailable in he cen e o he wo k sys em,
se o he app op ia e o que and equipped wi h he co -
ec bi . To ensu e su icien wo kplace illumina ion, i is
equipped wi h an LED illuminan —app ox. 2300lm and
app ox. 5000k. In addi ion, he wo ks a ion is shielded wi h
a co e pla e abo e he wo k sys em o p e en changes in
illumina ion. The assis ance sys em by RICOH desc ibed
a he beginning is also i mly moun ed abo e he wo k
sys em (see Fig. 4). On he le side o he wo ks a ion
a 19-inch sc een is moun ed a eye le el, which displays
he ele an assembly in o ma ion as well as eedback om
he assis ance sys em. An addi ional IP came a is loca ed
abo e he wo ks a ion in o de o minimize he in luence o
K
Zei sch i ü A bei swissenscha (2024) 78:240–253 245
RICOH
SC-10A (H)
Elec ic
sc ewd i e
Moni o
Assembly
ix u e
IP-Came a
Fig. 4 S udy se up (Bendzioch and Hin ichsen 2023, modi ied)
Abb. 4 Un e suchungsau bau (Bendzioch und Hin ichsen 2023, modi-
izie )
he es supe iso du ing he es p ocedu e. Wi h his, he
es p ocedu e can be moni o ed li e ia a sepa a e sc een
a a su icien dis ance om he es subjec —app ox. 3m.
4.1.4 Independen and dependen a iables
Based on he esea ch design desc ibed abo e, his s udy
uses wo ac o s, each wi h wo- ac o le els, as indepen-
den a iables—a wo-by- wo- ac o esea ch design. Wi h
he i s ac o , he ype o suppo is a ied in wo le els:
(1) in o ma ional assis ance sys em and (2) pape -based in-
o ma ion p o ision—con ol medium. The second ac o
comp ises he dis inc ion be ween wo g oups o indi idu-
als. The i s g oup consis s o indi iduals wi h cogni i e
impai men s (expe imen al g oup) who wo k in a wo kshop
o people wi h disabili ies. The indi iduals in he second
g oup ha e no cogni i e pe o mance limi a ions and ac
as a con ol g oup. Bo h g oups a e di ided in o wo sub-
g oups acco ding o he esea ch design—assis ance sys em
and pape -based ins uc ion.
Whe he and o wha ex en he wo g oups o indi id-
uals di e om and among each o he due o he use o
he in o ma ion-based assis ance sys em o he pape -based
assembly ins uc ion is examined based on he ollowing
dependen a iables: Du a ion o assembly o a p oduc (ex-
ecu ion ime), numbe o assembly e o s, numbe o pick-
ing e o s, assembly esul (co ec o inco ec ) and men al
s ess. The cha ac e is ics o he dependen a iables a e
eco ded o he assembly o each mul i-ou le powe s ip.
How da a on indi idual dependen a iables a e de e mined
is desc ibed in Sec . 4.2.2.
4.2 Gene al app oach
4.2.1 P e- and pos - es s
Th ee di e en p e- es s and one pos - es a e used in he
empi ical s udy, which a e desc ibed in mo e de ail below:
P e- es Collec ion o pe sonal da a: The pe sonal da a is
collec ed using a ques ionnai e. In addi ion o ques ions on
age, gende , and occupa ional s a us, he ques ionnai e also
includes ques ions on he pe o mance o assembly asks
and ca ee p ospec s. Since i canno gene ally be assumed
ha people wi h cogni i e impai men s can ead, w i e, and
calcula e, his is que ied as a basis o unde s anding he
subsequen assembly ins uc ions—basic unde s anding. In
addi ion, subjec s a e asked o p o ide a sel -assessmen
o hei manual dex e i y on a scale o 1 o 10, as well
as in o ma ion abou hei p io ask-speci ic expe ience.
Finally, he subjec s also ha e o make a s a emen abou
hei ca ee p ospec s wi h a ime ho izon o h ee yea s,
wi h he aim o highligh ing di e ences be ween he g oups
o indi iduals.
P e- es De e mina ion o isual acui y: The equi ed is-
ual acui y is checked wi h a s anda dized eye es by
Miß eld (n.d.). This es is an eye exam in A4 o ma ,
on which le e s a e shown in descending o de o size.
The smalles on size ha mus be ead in he es is used
as a e e ence o minimum isual acui y—labeling o he
g ipping con aine s. I should be no ed a his poin ha
indi iduals who ha e a isual aid mus pe o m bo h he
eye exam and he subsequen expe imen while wea ing i .
The eye exam is conside ed as passed i he smalles on
can be ead aloud a a dis ance o 110cm— he maximum
dis ance in he expe imen .
P e- es De e mina ion o mo o skills: In addi ion o he
subjec i e sel -assessmen o mo o skills and manual dex-
e i y, hey a e also checked wi h he aid o a e e ence
model. The e e ence model is a Lego®ca wi h 18 pa s
and is o be assembled in se en assembly s eps. Fo his
assembly, subjec s ecei e pape -based ins uc ions simi-
la in scope and s uc u e o hose used in he subsequen
main expe imen . The p e- es is comple ed when he e -
e ence model is assembled wi hou e o s. The mo o skills
a e e alua ed based on he execu ion ime equi ed wi hin
one g oup o indi iduals and in compa ison wi h he o he
g oups.
Pos - es De e mina ion o men al s ess: Subjec i ely pe -
cei ed s ess is eco ded a e each ully assembled mul i-
ou le powe s ip using a modi ied NASA-TLX ques ion-
nai e. Fo his pu pose, he ques ionnai e o Ha and S a e-
K
246 Zei sch i ü A bei swissenscha (2024) 78:240–253
land (1988) was adap ed o he needs o he g oup o indi-
iduals so ha i is easie o unde s and (“easy language”).
Acco dingly, he six i ems o he ques ionnai e a e as ol-
lows: 1. Men al equi emen —“Did you ha e o hink a li le
o a lo ?”, 2. Physical equi emen —“Did you ha e o mo e
a li le o a lo ?”, 3. Time equi emen —“Did you ha e o
hu y a li le o a lo ?”, 4. Pe o mance—“Did you do well
o poo ly on he ask?”, 5. E o —“Did you ha e o exe
a li le o a lo o e o ?”, and 6. F us a ion—“Did you
ge annoyed a li le o a lo by he ask?”. The indi idual
i ems a e a ed using a i e-poin Like scale. Following
P abaswa i e al. (2019), sco es o 0 o 1.5 co espond o
e y low men al s ess, 1.5 o 2.5 o low men al s ess,
2.5 o 3.5 o medium men al s ess, 3.5 o 4.5 o high men-
al s ess, and 4.5 o 5 o e y high men al s ess.
4.2.2 P ocedu e
Be o e he s a o an expe imen , he pa icipan s a e in-
o med e bally and in w i ing abou he p ocedu e, he
gene al condi ions, and he s udy objec i e. Subsequen ly,
he pe sonal da a a e collec ed, and he mo o and isual
abili ies a e checked using he p e- es s desc ibed abo e.
A e comple ing hese p e- es s, subjec s will be andomly
assigned o ei he he con ol medium (pape -based ins uc-
ions) o he assis ance sys em o pe o m he main expe -
imen , assembling he i e mul i-ou le powe s ips. The
in oduc ion o he espec i e suppo medium akes place
wi h he help o p epa ed documen s, which a e p esen ed
by he expe imen e . In addi ion o he in oduc ion o he
espec i e suppo medium, he pa icipan s also ecei e in-
s uc ions on assembly as well as on he use and unc ion
o he sc ewd i e . In addi ion, he heigh -adjus able wo k-
s a ion is se acco ding o he subjec ’s equi emen s.
Following he in oduc ion and p epa a ion o he main
expe imen , he mul i-ou le powe s ips a e moun ed in he
speci ied o de (see Fig. 3). The assembly p ocess as well
as he ime eco ding s a wi h he call-up o he assem-
bly ins uc ions on he sc een o he supply o he pape -
based ins uc ions and end wi h he comple ion o he las
wo k s ep o an assembly. The equi ed execu ion ime is
eco ded by he expe imen e using an Excel ool and e e s
o he comple e assembly o a mul i-ou le powe s ip. E -
o s du ing picking o assembly a e eco ded in a p e iously
c ea ed e o lis wi h he ollowing e o s: Tool no used,
componen moun ed in w ong posi ion, w ong o ien a ion
o componen , componen no moun ed, o he e o du ing
assembly and w ong componen g abbed (picking e o ).
Howe e , i mus be conside ed ha all e o s a e eco ded,
including hose co ec ed du ing assembly o picking. The
inal assembly esul o each mul iple socke powe s ip
is e alua ed by he es supe iso based on de ined c i e ia
and also logged. Du ing he pe iod o assessmen by he ex-
pe imen e , subjec s a e di ec ed o comple e he pos - es
desc ibed ea lie o de e mine subjec i ely pe cei ed s ess.
This way, he ques ionnai e is comple ed by each subjec
a o al o i e imes, so ha a s ess sequence is eco ded
ac oss he assemblies.
4.2.3 E alua ion
The da a collec ed du ing he expe imen a e analyzed bo h
desc ip i ely and by in e en ial s a is ical me hods using
he s a is ical p og am SPSS®28. The ocus is on he de-
ined dependen a iables, which a e in ended o e lec he
in luence o he assembly assis ance sys em on he wo
g oups o indi iduals compa ed o he con ol medium.
Based on hese a iables and he chosen esea ch design,
es p ocedu es sui able o he s udy o independen sam-
ples a e selec ed depending on he dis ibu ion—Shapi o-
Wilk es —and homogenei y o a iance—Le ene es —o
he da a se . Al hough he expe imen al design includes
mo e han wo s ages, he es p ocedu es used a e, on he
one hand, he - es and, on he o he hand, he Mann-Whi -
ney U- es ins ead o an analysis o a iance o he K uskal-
Wallis es . This ensu es ha only he es a iables ele an
o he s udy—e.g., expe imen al g oup assis ance sys em
s. con ol g oup pape ins uc ion—a e conside ed. This
is subs an ia ed, on he one hand, by he di e en p e eq-
uisi es o he wo g oups o indi iduals and he associa ed
di e ences in pe o mance and, on he o he hand, by he
ac ha he con ol g oup—assis ance sys em and pape
ins uc ion—was conside ed wice. Condi ions ha would,
o example, be included in he K uskal-Wallis es — ank
sum calcula ion—and hus lead o a bias in he esul s.
Fo all es s pe o med, he signi icance le el is α= 0.05,
wi h signi ican esul s (p<α) di ided in o h ee classes:
0.05> p> 0.01 signi ican , 0.01≥p> 0.001 e y signi ican ,
and p≤0.001 highly signi ican . In o de o subs an ia e he
signi icance o in luence o a signi ican esul , he e ec
s eng h is u he calcula ed using he co ela ion coe -
icien . Acco ding o Cohen’s de ini ion (Cohen 1992),
< 0.30 co esponds o a weak e ec , 0.30≤ < 0.50 o
a medium e ec , and ≥0.50 o a s ong e ec . The in-
e en ial s a is ical esul s a e supplemen ed by igu es and
ables on he loca ion and dis ibu ion o he da a using
desc ip i e analyses.
4.3 Pa icipan s
A o al o 20 subjec s wi h cogni i e impai men s (7 women
and 13 men) and 20 subjec s wi hou cogni i e pe o mance
impai men s (2 women and 18 men) pa icipa ed in he
empi ical labo a o y s udy (see Table 2). In o al, 10 indi-
iduals om he espec i e g oup can hus be conside ed
o each o he wo condi ion combina ions—compa ison
K
Zei sch i ü A bei swissenscha (2024) 78:240–253 247
Table 2 Pe sonal da a o he s udy pa icipan s
Tab. 2 Pe sonenbezogene Da en de Ve suchs eilnehmenden
People wi h disabili ies
—Expe imen al g oup
S uden s and academic s a
—Con ol g oup
Numbe o subjec s n=20
(7 women, 13 men)
n=20
(2 women, 18 men)
Age M = 34.30 [yea s]
SD= 14.34 [yea s]
M = 33.90 [yea s]
SD= 14.37 [yea s]
Reading, W i ing &
A i hme ic
Basic unde s anding me Basic unde s anding me
Line o wo k o he
subjec s
35% Assembly; 25% Voca ional aining; 20%
Me alwo king; 10% Joine y; 10% Tex iles
55% S udies wi h a echnical backg ound; 45% Resea ch
and eaching
Assessmen o own
manual dex e i y
M= 7.55; SD= 2.16 (on a scale o 1 o 10) M= 7.90; SD= 1.33 (on a scale o 1 o 10)
P ospec s o he nex
3 yea s
35% No idea;
30% Gene al labo ma ke ; 25% W bM; 10% Pen-
sion
45% Gene al labo ma ke ; 35% Con inued employmen a
TH OWL; 15% (Doc o a e) s udies; 5% Pension
medium pape s. assis ance sys em. Bo h g oups o indi-
iduals ha e a simila age s uc u e: Expe imen al g oup
M= 34.30 yea s (SD= 14.34 yea s) and con ol g oup M=
33.90 yea s (SD= 14.37 yea s). Subjec s in he expe imen al
g oup we e d awn om ypical wo k sec o s wi hin a wo k-
shop o people wi h disabili ies (W bM), such as assembly
o joine y, while subjec s in he con ol g oup we e s u-
den s and academic s a a he uni e si y. The examina ion
o he eading, w i ing, and a i hme ic skills showed ha he
p e equisi es o ca ying ou he labo a o y es we e me
in all subjec s. Bo h g oups o subjec s a e hei manual
dex e i y simila ly (see Table 2).
While es ing isual pe o mance, i was con i med ha
he pa icipa ing subjec s all had adequa e ision. The an-
swe s o he ques ion ega ding p e ious expe ience wi h
he expe imen al ask e ealed ha all subjec s had no ex-
pe ience wi h he assembly o mul i-ou le powe s ips.
Howe e , di e ences be ween he g oups o indi iduals
we e ound in he examina ion o mo o skills. This can
be seen in Table 3, which shows ha he execu ion ime, on
a e age (M), o assembling he Lego® e e ence model is
Table 3 Execu ion ime o he Lego® e e ence model using a pape -
based ins uc ion
Tab. 3 Aus üh ungszei des Lego®-Re e enzmodells un e de Ve -
wendung eine papie basie en Anweisung
M [s] SD [s] Numbe o
subjec s
Expe imen al g oup
To al 205.20 98.16 20
Assis ance sys em 195.80 91.46 10
Pape -based ins uc ions 214.60 108.52 10
Con ol g oup
To al 82.95 18.52 20
Assis ance sys em 74.90 15.07 10
Pape -based ins uc ions 91.00 18.78 10
signi ican ly highe o he expe imen al g oup han o he
con ol g oup. This di e ence also exis s wi h espec o
he s anda d de ia ion (SD). The la ge a ia ion in execu-
ion imes among he expe imen al g oup illus a es ha he
pe o mance le el o he subjec s—due o indi idual limi-
a ions—is e y di e en . Fu he mo e, i can be seen om
Table 3, conside ing he assis ance medium assigned la e in
he main expe imen , ha he execu ion imes o he espec-
i e g oup using he assis ance sys em end o be sligh ly
sho e (ex-pos obse a ion). Fo he con ol g oup, his
di e ence p o es signi ican using a - es ( (18)= 2.114,
p= 0.049, = 0.445).
Fu he examina ion o he da a se using a mean spli
(M= 144.07, SD= 93.24) also clea ly illus a es he di e -
ence be ween he wo g oups o indi iduals wi h espec o
he execu ion ime o he Lego® e e ence model. Table 4
shows ha all pa icipan s in he con ol g oup a e below he
o e all mean alue o 144.07s, while only eigh indi iduals
in he expe imen al g oup a e below his alue.
The ques ion he e o e a ises as o wha hese indings
mean o he u he conduc o he labo a o y expe imen .
In p inciple, hey e lec he cu en pe o mance ela ion-
ship o he wo g oups o indi iduals unde he same gen-
e al condi ions and we e o be expec ed gi en he spe-
ci ic limi a ions o he indi iduals om he expe imen al
g oup. Howe e , i mus also be conside ed ha he con-
ol g oup, which was assigned o he assis ance sys em a
a la e s age, assembled he e e ence model signi ican ly
as e and can hus gene ally be classi ied as pa icula ly
e icien . Likewise, his g ouping signi ies ha i ends o
become mo e di icul o indi iduals wi h cogni i e im-
pai men s o app oach his g oup o indi iduals, e en using
an in o ma ional assis ance sys em. Rega dless, he esul s
o he expe imen al g oup ep esen an expec ed ange o
sp ead in which he baseline le el can be classi ied as ap-
p oxima ely he same, conside ing he subsequen o m o
K
