Psychology
2011. Vol.2, No.9, 889-895
Copyright © 2011 SciRes. DOI:10.4236/psych.2011.29134
Dimensions in Appraising Fatigue in Relation to Performance
Arno van Dam1, Ger P. J. Keijsers2, Paul A. T. M. Eling3,
Eni S. Becker2
1GGZ-Westelijk Noord Brabant, Institute for Mental Health,
Bergen op Zoom, The Netherlands;
2Radboud University Nijmegen, Behavioural Science Institute,
Nijmegen, The Netherlands;
3Radboud University Nijmegen, Donders Institute for Brain, Cognition and Behaviour,
Nijmegen, The Netherlands.
Received September 3rd, 2011; revised October 8th, 2011; accepted November 12th, 2011.
Studies on the relation between fatigue and performance often fail to find a strong and direct link, implying that
multiple factors may be involved. A literature search on the fatigue-performance relationship suggests that two
different conceptual frameworks are employed concerning the appraisal of fatigue in relation to performance: an
adaptation-oriented framework and an emotion-related framework. In this study we investigated whether adapta-
tion-oriented appraisal and emotion-related appraisal exist as separate dimensions in a healthy population. A list
of statements derived from these frameworks was presented to 127 healthy individuals. A principal component
analysis revealed a six-factor solution and a three-factor solution of fatigue appraisal, closely related to the con-
ceptual frameworks. These findings are in line with our impressions from the literature that fatigue can be ap-
praised in an adaptation-oriented way and in an emotion-related way. In addition, we found a third factor: “so-
cial rejection because of fatigue”. We investigated whether the different appraisal dimensions were related to
general level of fatigue, anxiety and depression. Only emotion-related appraisal and general le vel o f f at ig u e we re
related. Worrying and focusing on fatigue is apparently related to the experience of fatigue whereas attributing
fatigue to the unrewarding properties of a task is not. Knowledge about the appraisal-dimensions underlying the
fatigue-performance relationship may contribute to a better understanding of individual differences in fatigue
effects on performance.
Keywords: Fatigue, Performance, Appraisal, Perception, C o g n i ti o n
Introduction
Fatigue is generally related to the time spent on a task and to
the demands of that task. This task-induced fatigue may result
in performance decrements, but the relation is in no way
straightforward. A large variation is observed among individu-
als with respect to the influence of fatigue on performance
(Boksem, Meijman, & Lorist, 2006), even more so in individu-
als suffering from disorders that are characterised by long-term
fatigue (DeLuca, 2005). Some studies show reduced cognitive
performance in fatigue-related syndromes (Van der Linden,
Keijsers, Eling, & Van Schaijk, 2005; Thomas & Smith, 2009),
while others do not (Short, McCabe, & Tooley, 2002).
It is not clear which factors underlie these large inter-indi-
vidual differences (Huibers et al., 2004; Nijrolder, Van der
Horst, & Van der Windt, 2008). Several authors suggest that
individual differences in appraisal of fatigue may be response-
ble (Afari & Buchwald, 2003; Knoop, Prins, Moss-Morris, &
Bleijenberg, 2010; Prins, Van der Meer, & Bleijenberg, 2006).
Appraisal refers to the interpretation of stimuli, situations or
symptoms. Fatigue, for example, may be appraised by an indi-
vidual as a signal that an activity is uninteresting or as a signal
that energy resources are getting depleted (Meijman, 1991).
Insight in the underlying dimensions in fatigue-appraisal may
provide clues for a better understanding of the complex relation
between fatigue and performance.
We performed a search in the PsychInfo and Medline data-
bases using combinations of the following keywords: fatigue,
performance, cognition and appraisal, looking for conceptual
frameworks concerning the appraisal of fatigue and its rela-
tionship with performance. We found several theories and
elaborated notions about the appraisal of fatigue in relation to
performance. Some were conceptually closely related to each
other whereas others were very different. We categorized the
theories and descriptions based on their conceptual differences
and similarities, resulting in two conceptual frameworks re-
garding the fatigue-performance relationship.
Adaptation-Oriented Ap praisal
In the fields of performance psychology and occupational
psychology, fatigue is often regarded as the result of an adap-
tive mental process that protects individuals from spending
effort on unrewarding activities. This idea has been elaborated
by authors such as Meijman (1991) and Boksem and Tops
(2008), and forms an important assumption in rather compara-
ble theories such as the effort-reward imbalance theory (Bellin-
grath, Weigl, & Kudielka, 2009; Siegrist, 2002), lack of recip-
rocity theory (Buunk & Schaufeli, 1993; Väänänen, Buunk,
Kivimäki, Vahtera, & Koskenvuo, 2008), and conservation of
resources theory (Alvaro et al., 2010; Hobfoll & Shirom, 1993).
According to these theories, individuals make cost-benefit analy -
ses of goal-directed behaviour to determine whether spending
effort is rewarding in terms of, for example, controllability,
chances of success, and attractiveness of the rewards (Boksem
& Tops, 2008; Dijksterhuis, 2004; Eccles & Wigfield, 2002;
Locke & Latham, 2002; Matthews, Davies, Westerman, &
Stammers, 2000). If the likelihood that spending effort will be
rewarding is experienced as small, individuals will (sub) con-

A. VAN DAM ET AL. 890
sciously tend to evaluate the goal-directed behaviour as nega-
tive. They will experience fatigue and aversion to spend further
effort and they will consequently reduce their efforts (Boksem
& Tops, 2008; Van Vegchel, De Jonge, Bosma, & Schaufeli,
2005).These theories are supported by findings from many
studies (see for a review: Van Vegchel et al., 2005) showing
that individuals, who perceive an imbalance in efforts and re-
wards, experience more fatigue than individuals without ex-
periencing such an imbalance. Moreover, experimental studies
show that changing the effort-reward balance by offering indi-
viduals a reward, can counteract fatigue (Boksem et al., 2006).
Although fatigue may act as a signal to reduce effort-expendi-
ture, individuals can ignore and override this fatigue for several
reasons, for example when they expect rewards in the long term,
or when they are overcommitted to their job. Overriding this
fatigue may be adaptive in emergency situations, but overriding
it for prolonged periods of time may lead to relatively perma-
nent stress, strain, illness and fatigue (Boksem & Tops, 2008).
Emotion-Related Appraisal
The second major framework on the appraisal of fatigue in
relation to performance can usually be found in the areas of
clinical and medical psychology. Here, emotion-related cogni-
tive processes, such as focusing on symptoms and worry, are
regarded as important factors for developing and maintaining
chronic fatigue. Several studies have shown that anxiety-related
appraisal plays a role in the perception of fatigue, affecting
performance, especially in chronic fatigue syndrome (CFS)
(Afari & Buchwald, 2003; Knoop et al., 2010).
First, focusing on bodily sensations plays a role in the per-
ception of fatigue in CFS. CFS patients are focused on bodily
sensations such as drowsiness and concentration problems.
They therefore perceive their fatigue as more intense than oth-
ers do (Afari & Buchwald, 2003; Knoop et al., 2010; Vercoulen
et al., 1998). Moreover, an enhanced focus on bodily sensations
requires attentional resources and thus negatively affects cogni-
tive performance (Van der Werf, De Vree, Van der Meer, &
Bleijenberg, 2002).
Second, fatigued individuals may perceive their fatigue as a
depletion of resources, restraining them to engage in activity
any longer. This kind of fatigue appraisal, often found in pa-
tients suffering from the burnout syndrome (Schaufeli &
Enzmann, 1998) or CFS (Afari & Buchwald, 2003), arouses
feelings of helplessness (McMullen & Krantz, 1988) and re-
duced self-efficacy (Findley, Kerns, Weinberg, & Rosenberg,
1998; Knoop et al., 2010).
Third, there appears to be a relation between worry, fatigue
and performance in chronic fatigue related syndromes (Sarason,
Sarason, & Pierce, 1990). A worry-related cognitive phenome-
non is catastrophizing which is known to influence fatigue and
performance in CFS. Several authors described that CFS pa-
tients are convinced that spending effort will have adverse ef-
fects on their health and are therefore reluctant to do so (Afari
& Buchwald, 2003; Knoop et al., 2010; Prins et al., 2006).
Fourth, fatigue also seems to be related to social anxiety.
Surawy, Hackman, Hawton, and Sharpe (1995) argued that
fatigued individuals believe that fatigue and the accompanying
reduced performance lead to rejection by others. This belief
prompts them to sustain high levels of effort and hence to per-
petuate fatigue.
Remarkably, we found no studies which incorporated both
frameworks. Apparently, there is little exchange of ideas about
the appraisal of fatigue and performance between the different
fields of fatigue research. Although there may be differences
between the populations studied in the two conceptual frame-
works, there are also similarities, since both frameworks are
applied to populations suffering from long term fatigue and
fatigue-related disabilities. Further, it is unclear whether these
different ways of fatigue appraisal actually exist as separate
dimensions and whether they are directly related to general
levels of fatigue or mood.
In this study we have tried to combine both frameworks and
investigated whether adaptation-oriented appraisal and emo-
tion-related appraisal exist as separate dimensions in a healthy
population.
Method
Participants
The municipal health department of Woensdrecht, a city in
the Netherlands, asked 500 randomly selected inhabitants to
complete a health inventory. Along with this health inventory
questionnaire, they also sent our list of statements.
Hundred-thirty-eight completed forms were returned (27.6%).
We excluded eleven participants who reported that they suf-
fered from a mental disorder. The age of the 127 participants
varied between 16 and 91 years with a mean of 48.6 and SD of
16.3; 64% of the participants were female. Level of education
was as follows: 46.5% had a low level of education, 31.5% a
medium level, and 22.0% a high level of education (See Table
1).
Rating Scale Fatigue-Performance Appraisal
In order to collect statements on the relation between fatigue
and performance we examined fatigue inventories in the scien-
tific literature (Ahsberg, Gamberale, & Kjellberg, 1997; Chal-
der et al., 1993; Hann, Denniston & Baker, 2000; Mendoza et a l.,
1999; Smets, Garssen, Bonke, & DeHaes, 1995; Vercoulen et
al., 1994). The collected inventories from the literature mainly
focus on various symptoms of fatigue like reduced concentra-
tion and passivity, and they do not explore the appraisal of fa-
tigue in relation to performance. Appraisals such as an individ-
ual’s view that fatigue is as a result of boring activities, or as
depletion of resources are not part of existing fatigue invento-
Table 1.
Sociodemographic featur es of the participants (N = 127).
Male 46 (36%)
Sex Female 81 (64%)
15 - 25 10 (8%)
25 - 35 13 (10%)
35 - 45 32 (25%)
45 - 55 27 (21%)
55 - 65 24 (19%)
65 - 75 12 (9%)
75 - 85 7 (6%)
Age
85 - 95 2 (2%)
Low 59 (46.5%)
Middle 40 (31.5%) Education level
High 28 (22.0%)

A. VAN DAM ET AL. 891
ries (see for a review: Christodoulou, 2005). Some fatigue in-
ventories such as the Fatigue Catatrophizing Scale (FCS;
Jacobsen, Azzarello, & Hann, 1999), the Illness Management
Questionnaire (IMQ: Ray, Weir, Stewart, Miller, & Hyde, 1993),
and the Fatigue Quality List (FQL; Gielissen et al., 2007) are
related to appraisal of fatigue, but were unsuitable for the pre-
sent study because they are developed for somatic patients and
mainly focus on medical attributions of fatigue, or are unrelated
to performance issues.
Because we were interested in the appraisal of fatigue in re-
lation to performance, we developed a set of statements based
on adaptation-oriented and emotion-related ways of appraising
fatigue and performance and we asked respondents to indicate
to what degree they agreed with each statement. For the adapta-
tion-oriented appraisal statements, we constructed two clusters
of five items each, comprising items on fatigue and reduced
performance as a result of motivational problems because the
task is perceived as uninteresting (cluster 1), or because the task
has no personal relevance (cluster 2). For the set of emotion-
related appraisal statements, we constructed four clusters of
five items, aiming to tap focusing on fatigue, catastrophizing,
resource depletion, and social exclusion because of fatigue. In
order to minimize chances on clustering of items on grammati-
cal aspects instead of content, the items were stated as much as
possible in a similar way: the 30 items were formulated in a
“When … Then” structure. For example: “When I am not able
to concentrate, (then) it means that I am not interested”. The 30
items were presented on paper in random order. Respondents
were asked to rate their agreement on a 7-point Likert scale
ranging from “strongly disagree” (score = 1) to “strongly
agree” (score = 7).
Before mailing the set of statements along with the health
inventory questionnaire, we first tested the statements in a pilot
study on 15 participants in order to check whether the items
were formulated in a clear way. The 15 participants were
healthy individuals working for a mental health institution. On
basis of their comments, we replaced three ambiguous items by
better alternatives. See Appendix 1 for the list of statements.
Measures
General fatigue was assessed with the Dutch version (Ver-
coulen, Alberts, & Bleijenberg, 1999) of the Checklist Individ-
ual Strength (CIS; Vercoulen et al., 1994). The 20 items meas-
ure subjective feelings of fatigue and physical fitness, activity
level, motivation, and concentration during the previous 14
days. Reliability and validity of the CIS are good, Cronbach’s
alpha for the CIS is .90 (Vercoulen et al., 1994).
Depression was measured with the depression subscale of the
Dutch adaptation (Arrindell & Ettema, 1986) of the Symptom
Checklist (SCL-90; Derogatis, 1977). The 16 items measure the
level of depressive symptoms during the past seven days. The
reliability and validity of the SCL-90 are good, Cronbach’s
alphas for the depression subscale of the SCL-90 range
from .88 to .99 (Arrindell & Ettema, 1986).
Level of anxiety symptoms was measured with the anxiety
subscale of the Dutch adaptationof the Symptom Checklist. The
10 items measure general anxiety symptoms during the past
seven days. Cronbach’s alphas for the anxiety subscale of the
SCL-90 range from .87 to .92 (Arrindell & Ettema, 1986).
Results
The scores on the 30 statements were subjected to a principal
component analysis (PCA), using varimax rotation. The Kai-
ser-Mayer-Oklin (KMO) measure showed proper sampling
adequacy (KMO > .79 exceeded the recommended value of .6,
which is considered as good). The KMO for one of the items of
the catastrophizing cluster was smaller than .5 and therefore the
item was excluded from further analyses. For the remaining
items, KMO ranged between .55 and .90, passing the accept-
able limit of .5. Bartlett’s test of sphericity reached statistical
significance (p < .001), supporting the factorability of the cor-
relation matrix. PCA revealed eight factors with eigenvalues
exceeding 1. Inspection of the screeplot revealed breaks after
the third and th e sixth factor.
It was decided to first perform a PCA forcing six factors. The
six-factor solution explained a total of 63.7% of the variance,
with Factors 1 to 6 contributing as follows to the explained
variance: 27.5%, 12.2%, 8.4%, 6.2%, 5.2% and 4.4%. Inspec-
tion of the items loading on the six factors revealed the follow-
ing content of the factors; see appendix 2 for details.
Factor 1: Six items from the “uninteresting” and “no personal
relevance clusters” loaded on this factor (internal consistency
reliability is high, Cronbach’s alpha is .87). A high score on
Factor 1 indicates that respondents relate reduced cognitive
performance, such as concentration problems, to activities
which they consider as unimportant or unrewarding and there-
fore are unwilling to spend effort. We referred to this factor as:
“reduced cognitive performance due to motivational problems”.
Factor 2: All five items from the “resource depletion cluster”
loaded on this factor (internal consistency reliability is high,
Cronbach’s alpha is .82). A high score on Factor 2 indicates
that fatigue is related to energy depletion and that respondents
believe that fatigue will lead to reduced cognitive performance.
We referred to this fa ct or as: “resource depletion” .
Factor 3: All five items from the “social rejection cluster”
loaded on this factor (internal consistency reliability is high,
Cronbach’s alpha is .84). A high score on Factor 3 indicates
that respondents believe that fatigue will lead to social rejection.
We referred to this factor as: “social rejection because of fa-
tigue”.
Factor 4: Four items from the “focusing on fatigue cluster”
and one from the “catastrophizing cluster” loaded on this factor
(internal consistenc y reliability is high, Cronbach’s alpha is .84).
A high score on Factor 4 indicates that respondents view per-
formance decrements, such as concentration problems, as signs
of fatigue. We referred to this factor as: “focusing on fatigue”.
Factor 5: Four items from the “uninteresting” and “no per-
sonal relevance clusters” loaded on this facor (internal consis-
tency reliability is high, Cronbach’s alpha is .84). A high score
on Factor 5 indicates that respondents relate fatigue to activiti es
which they consider as unimportant or unrewarding and there-
fore are unwilling to spend effort. We referred to this factor as:
“fatigue due to mo ti vat ion al problems”.
Factor 6: Three items from the catastrophizing cluster and
one from the focusing on fatigue cluster loaded on this factor
(internal consistency reliability is moderate, Cronbach’s alpha
is .67). A high score on Factor 6 indicates that a respondent
believes that spending effort while fatigued is harmful to one’s
health. We referred to this factor as : “catastrophizing”.
Because the screeplot also allowed a three factor solution, we
investigated whether a reduction to three factors would lead to a
meaningful alternative solution. The three-factor solution ex-
plained a total of 48.3% of the variance with Factor 1 contrib-
uting 27.8% of the variance, Factor 2 contributing 12.2 percent
of the variance, and Factor 3 contributing 8. 4% of the va riance.
Inspection of the item loadings revealed the following, see ap-

A. VAN DAM ET AL. 892
pendix 2 for details.
Factor 1: All 10 items of the adaptation-oriented framework
loaded on this factor (internal consistency reliability is high,
Cronbach’s alpha is .89). A high score on Factor 1 indicates
that respondents relate fatigue and reduced cognitive perform-
ance, such as concentration problems, to activities which they
consider as unimportant or unrewarding and which they there-
fore are unwilling to spend effort on. We referred to this factor
as “adaptation-oriented appraisal”.
Factor 2: Four items from the “catastrophizing cluster”, five
items from the “resource-depletion cluster” and four items from
the “focusing on fatigue cluster” loaded on this factor (internal
consistency reliability is high, Cronbach’s alpha is .85). A high
score on Factor 2 indicates that respondents relate fatigue to
energy depletion, that the respondents believe that spending
effort is harmful to their health, and that they are focussed on
signs of fatigue. We referred to this factor as “emotion-related
appraisal”.
Factor 3: Five items from the “social exclusion cluster” and
one item of the focusing on fatigue cluster loaded on this factor
(internal consistenc y reliability is high, Cronbach’s alpha is .83).
A high score on Factor 3 indicates that respondents believe that
fatigue will lead to social rejection and that they are focussed
on signs of fatigue. We referred to this factor as “social reject-
tion”. Interestingly, the three factor solution reflected the two
conceptual frameworks: adaptation-oriented appraisal and emo-
tion-related appraisal, with an additional third factor: social
rejection.
We calculated correlations between the factor scores of both
solutions and the scores on the CIS, the anxiety subscale and
the depression subscale of the SCL-90. Only the correlation
between Factor 2 of the three-factor solution and the CIS
reached statistical significance, r = .30, p < .001. Focusing on
fatigue was the only emotion-related factor of the six-factor
solution that was related to the CIS, r = .25, p < .05. Correla-
tions between the CIS, the anxiety subscale and the depression
subscale of the SCL-90 revealed that general fatigue correlated
with anxiety, r = .29, p < .001.
Discussion
In the literature on fatigue and performance, we observed
two conceptual frameworks on the cognitive appraisal of this
relation: an adaptation-oriented framework, which concerns the
regulation of effort-expenditure, and an emotion-related frame-
work, which concerns the regulation of emotion. Remarkably,
we found no studies which incorporated both frameworks. In
this study we tried to combine both frameworks and investi-
gated whether adaptation-oriented appraisal and emotion-re-
lated appraisal exist as separate dimensions in a healthy popula-
tion. We presented respondents with a set of statements about
possible relations between fatigue and performance based on
the two frameworks. A principal component analysis revealed
six factors, with each factor corresponding to a specific aspect
of the two frameworks. A three-factor solution revealed adapta-
tion-oriented appraisal, emotion-related appraisal, and social
rejection as separate factors. Although the six-factor solution
explained more variance than the three-factor solution and of-
fers a more differentiated view on fatigue-performance ap-
praisal, we think that the three-factor solution is more appropri-
ate for the discussion of our study as the purpose of our study
was to investigate whether the frameworks on fatigue-perfor-
mance appraisal found in the literature, could be distinguished
in a healthy population.
The findings of our study are in line with our impressions
from the literature that fatigue can be appraised in an adapta-
tion-oriented way and in an emotion-related way. Moreover,
although much of the literature on appraisal of fatigue, espe-
cially emotion-related appraisal, concerns patients suffering
from long-term fatigue, adaptation-oriented appraisal and an
emotion-related appraisal of fatigue and performance can ap-
parently also be found in a healthy population.
Apart from the two frameworks derived from the literature,
we found a third factor: “social rejection”. Social rejection may
have emerged as a separate factor because fear of social reject-
tion is associated by individuals with the consequences of fa-
tigue, such as reduced performance, and not to appraisal of
fatigue (Prins et al., 2004). Furthermore, “fear for social reject-
tion” is likely to lead to an increase in effort expenditure
(Surawy et al., 1995), whereas emotion-related appraisal and
adaptation-oriented appraisal lead to a decrease in effort-ex-
penditure when fatigued.
Emotion-related appraisal was related to general level of fa-
tigue. It is not surprising that this was the only relation between
the appraisal dimensions and general level of fatigue, anxiety
and depression, because general cognitions about the appraisal
of fatigue are not necessarily related to current levels of fatigue
or mood in a healthy population with relative low scores on
these measures.
An explanation for the observed relation between focusing
on fatigue and fatigue is in line with several studies that showed
that focusing on signs of fatigue is related to level of fatigue
(Knoop et al., 2010). Individuals who are inclined to interpret
reduced performance as signs of fatigue, apparently perceive
more fatigue than individuals who are not.
General level of anxiety and general level of fatigue ap-
peared to be related, which is in line with studies that showed
that neuroticism is a predictor of elevated levels of fatigue
(Harvey, Wessely, Kuh, & Hotopf, 2009).
In summary, the results of our study suggest that adaptation-
oriented and emotion-related appraisal can be distinguished as
separate dimensions of fatigue-appraisal in a healthy population
with normal levels of fatigue. Emotion-related appraisal is re-
lated to general level of fatigue, whereas adaptation-oriented
appraisal is not. Worrying and focusing on fatigue is apparently
related to the experience of fatigue whereas attributing fatigue
to the unrewarding properties of a task is not.
Our finding that general level of fatigue is related to emo-
tion-related appraisal and not to adaptation-oriented appraisal
may explain why the emotion-related framework is mainly
studied in the fields of clinical and medical psychology and the
adaptation-oriented framework is mainly studied in the fields of
occupational and performance psychology.
It would be interesting to know whether the two conceptual
frameworks on fatigue and performance can also be distin-
guished in a population of patients suffering from long term
fatigue and whether they report more emotion related appraisal
than adaptation related performance. Gielissen et al. (2007)
showed that CFS patients perceived fatigue as more negative
compared to healthy controls. It is not known, however, to what
degree fatigue is also appraised as adaptive by individuals suf-
fering from long-term fatigue. We are preparing a paper on a
study with the measures applied in the present study in a popu-
lation of patients suffering from burnout as well as patients
suffering from depression and anxiety disorders.
The present study has a number of limitations. The response
to the set of statements was only 28 percent. We have no indi-

A. VAN DAM ET AL. 893
cations however, how the limited response may have affected
our results. What we can say is that the group of participants
that did respond did not differ from the whole sample on demo-
graphic variables. Further, self-report measurement of apprais-
als, the way we applied it in the present study, implies that im-
plicit aspects of fatigue-performance appraisals were not taken
into account. An interesting line of research (e.g., Dijksterhuis,
2004) shows, however, that people have incomplete access to
their appraisals. Finally, one should keep in mind that in the
present study appraisals about performance were measured and
not performance itself. Appraisal or perception of performance
may be quite different from actua l performance (se e e.g. Metzger
& Denney, 2002).
Despite these limitations, we think that the present study
shows that adaptation-oriented appraisal, emotion-related ap-
praisal and “fear of social exclusion because of fatigue” can be
distinguished as separate dimensions in a healthy population.
This finding may be useful for researchers studying fatigue in
for example the working situation or in clinical syndromes.
Knowledge about the appraisal-dimensions underlying the
fatigue-performance relationship may contribute to a better
understanding of individual differences in fatigue effects on
performance. Longitudinal research in populations suffering
from fatigue and in healthy individuals may shed more light on
the relevance of individual differences in appraisal of fatigue
for performance.
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Appendix 1: Statements on the Appraisal of
Fatigue in Relation to Performance (English
Translation)
1) When I am getting tired, it means I do not enjoy what I am
doing at that moment.
2) When I am getting tired, it means that I do not consider
what I am doing at that moment as important
3) If you are frequently tired, you do not matter anymore.
4) When I am doing something and I have problems concen-
trating it means I do not feel like doing what I am doing.
5) When I have to do something boring, I get tired quickly.
6) When I am tired and I keep on making an effort, it only
gets worse.
7) When I get tired, I can not focus on what I am doing.
8) When I am tired, I am not able to concentrate anymore.
9) When I have to do something which I do not consider as
meaningful, I get tired easily.
10) When I am tired, I am not able to take part in a conversa-
tion anymore
11) When I get trouble concentrating it means that what I am
doing at the moment is not interesting.
12) If you are frequently tired, people will consider you as
troublesome.
13) When I have trouble concentrating it means that what I
am doing at that moment I do not consider as important.
14) When I can not concentrate during a conversation it
means that the convers ation is actually no t enjoyable.
15) If you are frequently tired, people will not take you seri-
ously anymore.
16) Making an effo rt is harmful when you ar e exhausted.
17) When I can not concentrate, it means that what I am do-
ing is not important to me.
18) When I am tired, I feel I run out of steam and cannot go
on.
19) If you are frequently tired, you do not mean anything
according to others.
20) When I forget something easily it means that I am tired.
21) When I cannot keep my attention during a conversation
it means that it actually is not an importan t conversation to me.
22) If you are ofte n tired, people do not t a ke you seriously.
23) When a certain word does not come to my mind it means
that I am tired.
24) When I have difficulty concentrating it means that I am
tired.
25) When I am tired, I am not capable to do anything.
26) I always pay attention to whether I am tired or not.
27) I have to take a rest when I am tired, otherwise I become
ill.
28) When I have difficulty expressing myself properly it
means that I am tired.
29) When I cannot concentrate during a conversation it
means that I am not well.
Appendix 2: Distribution of Items over the
Clusters and Dimensions of
Fatigue-Performance Appraisal
A priori clusters Items
Adaptational framework
Not interesting 1, 4, 5, 11, 14
No relevance 2, 9, 13, 17, 21
Anxiety-rela ted framework
Focusing on fatigue 20, 23, 24, 26, 28
Resource depletion 7, 8, 10, 18, 25
Catastroph i zing 6, 16, 27, 29
Social reje ction 3, 12, 15, 19, 22
Three factor solution
1) Adaptati o n-oriented appraisal 1, 2, 4, 5, 9, 11, 13, 14, 17, 21
2) Emotion-re l ated appraisal 6, 7, 8, 10, 16, 18, 23, 24, 25,
26, 27, 28, 2 9
3) Social rejection 3, 12, 15, 19, 20, 22
Six factor solution
1) Reduced cognitive pe r for mance due
to motivational problems 4, 11, 13, 14, 17, 21
2) Resourc e depletion 7, 8, 10, 18, 25
3) Social rejection because of fatigue 3, 12, 15, 19, 22
4) Focusing on fatigue 20, 23, 24, 28, 29
5) Fatigue due to motivational problems 1, 2, 5, 9
6) Catastro p hizing 6, 16, 26, 27