Journal of Trauma & Dissociation
ISSN: 1529-9732 (Print) 1529-9740 (Online) Journal homepage: http://www.tandfonline.com/loi/wjtd20
Psychometric Properties of the Adolescent Dissociative Experiences Scale (A-DES) in a Sample of Italian Adolescents Adriano Schimmenti PhD, DClinPsych To cite this article: Adriano Schimmenti PhD, DClinPsych (2015): Psychometric Properties of the Adolescent Dissociative Experiences Scale (A-DES) in a Sample of Italian Adolescents, Journal of Trauma & Dissociation, DOI: 10.1080/15299732.2015.1064507 To link to this article: http://dx.doi.org/10.1080/15299732.2015.1064507
Accepted author version posted online: 09 Jul 2015.
Submit your article to this journal
Article views: 31
View related articles
View Crossmark data
Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=wjtd20 Download by: [NUS National University of Singapore]
Date: 06 November 2015, At: 16:01
Psychometric Properties of the Adolescent Dissociative
cr ip
us
Adriano Schimmenti, PhD, DClinPsych
M an
This manuscript:
1. is original and has not been published before and will not be submitted for publication elsewhere while under consideration of the Journal of Trauma & Dissociation;
ed
2. does not infringe any copyright, right of privacy or libellous material; 3. does not infringe any duty of confidentiality;
pt
4. it is consistent with the principles of research ethics of the Italian Psychological Association
ce
and the American Psychological Association. Conflict of interests: none to be declared.
Ac
Downloaded by [NUS National University of Singapore] at 16:01 06 November 2015
Adolescents
t
Experiences Scale (A-DES) in a Sample of Italian
Running Head: ITALIAN A-DES Keywords: Adolescent Dissociative Experience Scale; A-DES; Dissociation; Reliability; Validity.
Correspondence: Prof. Adriano Schimmenti, PhD, DClinPsych,
cr ip
t
Faculty of Human and Social Sciences, UKE – Kore University of Enna,
us
Phone: (+39)3286267944. E-mail: [email protected]
ACKNOWLEDGEMENTS: The Author is grateful to Vincenzo Caretti and Giuseppe Craparo,
M an
who gave expert inputs for the Italian translation of the A-DES. Abstract
The purpose of this study was to examine the psychometric properties of the Italian translation of
ed
the Adolescent Dissociative Experiences Scale (A-DES). A sample of
1,806 high-school
students aged 13 to 18 years, recruited in 6 Italian cities, completed the A-DES. The A-DES
pt
showed high internal consistency, excellent item-to-scale homogeneity, good split-half
ce
reliability, and a single factor structure. The scores of Italian adolescents were comparable to those found in previous research with the measure. No gender differences were found in mean ADES scores, but boys and girls showed different patterns of response on A-DES items. Age
Ac
Downloaded by [NUS National University of Singapore] at 16:01 06 November 2015
Cittadella Universitaria 94100, Enna, Italy.
differences were also found, with 13- and 18-years old students scoring higher on the measure than the other participants. A cluster analysis showed that participants could be consistently
grouped in two clusters of low- and high-dissociative adolescents. This study supported the ADES as a reliable and valid screening measure for dissociative symptoms in adolescents.
KEYWORDS: Adolescent Dissociative Experiences Scale; A-DES; Dissociation; Adolescents; Validity; Reliability. Psychometric Properties of the Adolescent Dissociative Experiences Scale (A-DES) in a Sample
t cr ip
Dissociative symptoms may be difficult to address in clinical practice, but it might be even more
us
difficult to recognize them when they occur during adolescence. As it is suggested in the DSM-5 (American Psychiatric Association, 2013), “dissociation may involve a disruption of and/or a
M an
discontinuity in the normal integration of consciousness, memory, identity, emotion, perception, body representation, motor control, and behavior” (p. 291). It is noteworthy that during adolescence young people experience many physical and psychological changes, and discontinuities in the self are normal in this life stage. Therefore, dissociative experiences in
ed
adolescence may not necessarily indicate psychological problems: for example, they could relate to normal developmental processes, such as the struggle for identity achievement (Pace &
pt
Zappulla, 2009), or the development and integration of a consistent self-image
(Di Blasi,
ce
Cavani, Lo Baido, La Grutta, & Schimmenti, 2015). However, dissociative experiences might also be indicators of a deep “developmental failure to coherently bind together the statedependent aspects of self” (Putnam, 1997, p. 176). Likely, such a failure is related to negative
Ac
Downloaded by [NUS National University of Singapore] at 16:01 06 November 2015
of Italian Adolescents
attachment experiences. Findings from longitudinal studies support the view that adolescents who were exposed to parental neglect and/or emotional abuse in childhood are at
disproportionate risk for developing severe dissociative symptoms (Dutra, Bureau, Holmes, Lyubchik, & Lyons-Ruth, 2009; Ogawa, Sroufe, Weinfield, Carlson, & Egeland, 1997).
Moreover, a history of child abuse and neglect has been consistently associated with increased levels of dissociative symptoms in adolescence (e.g., Armstrong et al., 1997; Kisiel & Lyons, 2001; Shin et al., 2009), and with many psychiatric disorders, such as post-traumatic stress
cr ip
t
disorder (Carlson, Dalenberg, & McDade-Montez, 2012), borderline personality disorder
disorders (Sar, Onder, Kilincaslan, Zoroglu, & Alyanak, 2014), among others. Dissociative
us
experiences were also linked to a number of problem behaviors in adolescence (Keck Seeley, Perosa, & Perosa, 2004), including deliberate self-harm (Kisiel & Lyons, 2001), unintended
M an
pregnancy (Madigan, Vaillancourt, McKibbon, & Benoit, 2012), and substance abuse (Caretti, Craparo, & Schimmenti, 2006), just to name a few.
Thus, assessing the frequency and severity of dissociative symptoms in adolescence could be
ed
relevant for both prevention and treatment purposes. Dissociative symptoms may include absorption and imaginative involvement (a very intense focusing of attention), depersonalization
pt
(distortions in the perceptions of one’s own body), amnesia (the inability to recall a significant segment of time), derealization (a sense that surroundings are unreal), up to disturbance in
ce
identity (passive influence and feelings of being more than one person). The Adolescent Dissociative Experiences Scale (A-DES; Armstrong, Putnam, Carlson, Libero,
Ac
Downloaded by [NUS National University of Singapore] at 16:01 06 November 2015
(Zanarini, Frankenburg, Jager-Hyman, Reich, & Fitzmaurice, 2008), and (obviously) dissociative
& Smith, 1997) is a short, easy-to-use measure which aims to capture both normal and
pathological dissociative experiences in adolescents. The A-DES has been cross-culturally
validated with positive results (e.g., Brunner, Parzer, Schuld, & Resch, 2000; Farrington, Waller, Smerden, & Faupel, 2001; Nilsson & Svedin, 2006; Shin, Jeong, & Chung, 2009; Soukup,
Papežová, Kuběna, & Mikolajová, 2010; Tolmunen et al., 2007; Yoshizumi, Hamada, Kaida, Katafumi, & Murase, 2010; Zoroglu, Sar, Tuzun, Tutkun, & Savas, 2002), and it is used worldwide to assess dissociative symptoms in adolescence. Given the relevance of the A-DES
cr ip
t
for the study of dissociation, it is important to provide researchers with further details about its
from the author of this study. Research with this translation has already shown that A-DES
us
scores are associated with post-traumatic symptoms and affect dysregulation (Caretti, Craparo, Ragonese, & Schimmenti, 2005; Caretti, Craparo, & Schimmenti, 2006; Schimmenti, Albasi,
M an
Lasorsa, Porcellini, & Granieri, 2005), and are predictive of substance misuse among adolescents (Caretti, Craparo, & Schimmenti, 2006). However, the psychometric properties of the A-DES in Italy were not fully explored until now. Therefore, the aim of the current study was to test the
ed
internal reliabilty and factor structure of the A-DES in a large non-clinical sample from Italy.
Participants
pt
Methods
ce
The study involved 1,806 high-school students (1,055 females, 58.4%; 751 males, 41.6%) recruited in 18 public schools specialized in different subjects (such as classical studies, teacher training, science, accountancy, languages, industrial engineering, tourism and hotel management)
Ac
Downloaded by [NUS National University of Singapore] at 16:01 06 November 2015
psychometric properties. The Italian translation of the A-DES was already available in 2005
from 6 cities (3 with over 1 million citizens, 3 with less than 200,000 citizens) in the North,
Center, and South of Italy. Participants ranged in age between 13 and 18 years (M=16.23; SD=1.60): 101 (5.6%) were 13 years old, 255 (14.1%) were 14 years old, 240 (13.3%) were 15
years old, 280 (15.5%) were 16 years old, 385 (21.3%) were 17 years old, and 545 (30.2%) were
18 years old. There was no significant association between gender and age of participants (χ2 (5) =1.20, p=.94, ns).
t
Procedures
cr ip
(English to Italian). A bilingual research assistant whose mother-tongue was English translated it
us
back to the original language (Italian to English), blind to the original version. Differences in the original and the back-translated versions were discussed until a consensus on cross-language
M an
equivalence was reached by joint agreement of both translators, with expert inputs further provided by other Italian scholars on dissociation (see Acknowledgements). In order to investigate the psychometric properties of the A-DES in Italy, the head teachers of 18 Italian high-schools were contacted. The objective of the study was described, and after ethical
ed
clearance they allowed researchers to administer the A-DES to their students. The students were informed about the nature of the study. Adult students signed an informed consent; parental
pt
informed consent was obtained from other students. Students completed the A-DES in their
ce
classrooms. This study was conducted in compliance with the author’s University Internal Review Board for psychological research. Measure
Ac
Downloaded by [NUS National University of Singapore] at 16:01 06 November 2015
The author of this study translated the A-DES from the original language to the second language
The Adolescent Dissociative Experiences Scale (A-DES; Armstrong et al., 1997) is a 30-item
self-report measure assessing the frequency of dissociative experiences in adolescents. The answers to the A-DES are marked on an 11-point scale ranging from 0 (never) to 10 (always).
The total A-DES score is the mean of all item scores. Thus, A-DES scores can range from 0 to 10, with higher scores indicating higher frequency of dissociative experiences. A mean score of 4 or above is usually considered an indicator of pathological dissociation, discriminating between
cr ip
t
adolescents with dissociative disorders and other adolescents (Armstrong et al., 1997). It was
imaginative involvement, amnesia, depersonalization/derealization, and passive influence).
us
However, studies on the factor structure of the A-DES showed that the 4-factor structure do not fit the data well in many samples, and often a single factor structure was preferred (Farrington et
M an
al. 2001; Nilsson & Svedin, 2006; Muris, Merckelbach, & Peeters, 2003; Shin et al., 2009). The A-DES has excellent internal consistency and test-retest stability, and it has proven to be valid across different cultural settings (Soukup et al., 2010). Given some exceptions (Nilsson & Svedin, 2006; Chabrol, Saint-Martin, Sejourné, Moyano, 2009; Yoshizumi et al., 2010), studies
ed
reported no gender or age differences in A-DES scores (Armstrong et al., 1997; Brunner et al.,
pt
2000; Farrington et al., 2001; Shin et al., 2009; Smith & Carlson, 1996; Zoroglu et al., 2002).
ce
Data analysis
Exploratory and confirmatory factor analyses were run to investigate the factor structure of the A-DES in the sample. Internal reliability and item-to-scale homogeneity of the A-DES were
Ac
Downloaded by [NUS National University of Singapore] at 16:01 06 November 2015
suggested that the A-DES theoretically comprises four symptom facets (absorption and
evaluated by calculating its Cronbach’s alpha coefficient, Spearman-Brown split-half reliability, and average inter-item correlations. Descriptive statistics were computed for the mean A-DES scores and for all the items the A-DES comprises. Differences in A-DES scores in relation to gender and age groups were tested through t-test and analysis of variance. A cluster analysis was
undertaken to classify participants into different groups according to their scores on A-DES items. A p value of 0.05 was set as the critical level for statistical significance.
t
Results
cr ip
derived 4-factor structure originally proposed for the A-DES (including absorption and
us
imaginative involvement, amnesia, depersonalization/derealization, and passive influence; see Armstrong et al., 1997) would adequately fit the data. The fit indices of the 4-factor structure
M an
were unsatisfactory (χ2=2849.75, df=399, χ2/df=7.14, SRMR=.046, CFI=.84, NNFI=.85, RMSEA=.058). Therefore, the structure of the A-DES was explored using principal component analysis. The sample size was excellent for this kind of analysis (Keyser-Meyer-Olkin=.96), and the population correlation matrix was not an identity matrix (Bartlett’s χ2 (435) = 17,720.66,
ed
p
ISSN: 1529-9732 (Print) 1529-9740 (Online) Journal homepage: http://www.tandfonline.com/loi/wjtd20
Psychometric Properties of the Adolescent Dissociative Experiences Scale (A-DES) in a Sample of Italian Adolescents Adriano Schimmenti PhD, DClinPsych To cite this article: Adriano Schimmenti PhD, DClinPsych (2015): Psychometric Properties of the Adolescent Dissociative Experiences Scale (A-DES) in a Sample of Italian Adolescents, Journal of Trauma & Dissociation, DOI: 10.1080/15299732.2015.1064507 To link to this article: http://dx.doi.org/10.1080/15299732.2015.1064507
Accepted author version posted online: 09 Jul 2015.
Submit your article to this journal
Article views: 31
View related articles
View Crossmark data
Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=wjtd20 Download by: [NUS National University of Singapore]
Date: 06 November 2015, At: 16:01
Psychometric Properties of the Adolescent Dissociative
cr ip
us
Adriano Schimmenti, PhD, DClinPsych
M an
This manuscript:
1. is original and has not been published before and will not be submitted for publication elsewhere while under consideration of the Journal of Trauma & Dissociation;
ed
2. does not infringe any copyright, right of privacy or libellous material; 3. does not infringe any duty of confidentiality;
pt
4. it is consistent with the principles of research ethics of the Italian Psychological Association
ce
and the American Psychological Association. Conflict of interests: none to be declared.
Ac
Downloaded by [NUS National University of Singapore] at 16:01 06 November 2015
Adolescents
t
Experiences Scale (A-DES) in a Sample of Italian
Running Head: ITALIAN A-DES Keywords: Adolescent Dissociative Experience Scale; A-DES; Dissociation; Reliability; Validity.
Correspondence: Prof. Adriano Schimmenti, PhD, DClinPsych,
cr ip
t
Faculty of Human and Social Sciences, UKE – Kore University of Enna,
us
Phone: (+39)3286267944. E-mail: [email protected]
ACKNOWLEDGEMENTS: The Author is grateful to Vincenzo Caretti and Giuseppe Craparo,
M an
who gave expert inputs for the Italian translation of the A-DES. Abstract
The purpose of this study was to examine the psychometric properties of the Italian translation of
ed
the Adolescent Dissociative Experiences Scale (A-DES). A sample of
1,806 high-school
students aged 13 to 18 years, recruited in 6 Italian cities, completed the A-DES. The A-DES
pt
showed high internal consistency, excellent item-to-scale homogeneity, good split-half
ce
reliability, and a single factor structure. The scores of Italian adolescents were comparable to those found in previous research with the measure. No gender differences were found in mean ADES scores, but boys and girls showed different patterns of response on A-DES items. Age
Ac
Downloaded by [NUS National University of Singapore] at 16:01 06 November 2015
Cittadella Universitaria 94100, Enna, Italy.
differences were also found, with 13- and 18-years old students scoring higher on the measure than the other participants. A cluster analysis showed that participants could be consistently
grouped in two clusters of low- and high-dissociative adolescents. This study supported the ADES as a reliable and valid screening measure for dissociative symptoms in adolescents.
KEYWORDS: Adolescent Dissociative Experiences Scale; A-DES; Dissociation; Adolescents; Validity; Reliability. Psychometric Properties of the Adolescent Dissociative Experiences Scale (A-DES) in a Sample
t cr ip
Dissociative symptoms may be difficult to address in clinical practice, but it might be even more
us
difficult to recognize them when they occur during adolescence. As it is suggested in the DSM-5 (American Psychiatric Association, 2013), “dissociation may involve a disruption of and/or a
M an
discontinuity in the normal integration of consciousness, memory, identity, emotion, perception, body representation, motor control, and behavior” (p. 291). It is noteworthy that during adolescence young people experience many physical and psychological changes, and discontinuities in the self are normal in this life stage. Therefore, dissociative experiences in
ed
adolescence may not necessarily indicate psychological problems: for example, they could relate to normal developmental processes, such as the struggle for identity achievement (Pace &
pt
Zappulla, 2009), or the development and integration of a consistent self-image
(Di Blasi,
ce
Cavani, Lo Baido, La Grutta, & Schimmenti, 2015). However, dissociative experiences might also be indicators of a deep “developmental failure to coherently bind together the statedependent aspects of self” (Putnam, 1997, p. 176). Likely, such a failure is related to negative
Ac
Downloaded by [NUS National University of Singapore] at 16:01 06 November 2015
of Italian Adolescents
attachment experiences. Findings from longitudinal studies support the view that adolescents who were exposed to parental neglect and/or emotional abuse in childhood are at
disproportionate risk for developing severe dissociative symptoms (Dutra, Bureau, Holmes, Lyubchik, & Lyons-Ruth, 2009; Ogawa, Sroufe, Weinfield, Carlson, & Egeland, 1997).
Moreover, a history of child abuse and neglect has been consistently associated with increased levels of dissociative symptoms in adolescence (e.g., Armstrong et al., 1997; Kisiel & Lyons, 2001; Shin et al., 2009), and with many psychiatric disorders, such as post-traumatic stress
cr ip
t
disorder (Carlson, Dalenberg, & McDade-Montez, 2012), borderline personality disorder
disorders (Sar, Onder, Kilincaslan, Zoroglu, & Alyanak, 2014), among others. Dissociative
us
experiences were also linked to a number of problem behaviors in adolescence (Keck Seeley, Perosa, & Perosa, 2004), including deliberate self-harm (Kisiel & Lyons, 2001), unintended
M an
pregnancy (Madigan, Vaillancourt, McKibbon, & Benoit, 2012), and substance abuse (Caretti, Craparo, & Schimmenti, 2006), just to name a few.
Thus, assessing the frequency and severity of dissociative symptoms in adolescence could be
ed
relevant for both prevention and treatment purposes. Dissociative symptoms may include absorption and imaginative involvement (a very intense focusing of attention), depersonalization
pt
(distortions in the perceptions of one’s own body), amnesia (the inability to recall a significant segment of time), derealization (a sense that surroundings are unreal), up to disturbance in
ce
identity (passive influence and feelings of being more than one person). The Adolescent Dissociative Experiences Scale (A-DES; Armstrong, Putnam, Carlson, Libero,
Ac
Downloaded by [NUS National University of Singapore] at 16:01 06 November 2015
(Zanarini, Frankenburg, Jager-Hyman, Reich, & Fitzmaurice, 2008), and (obviously) dissociative
& Smith, 1997) is a short, easy-to-use measure which aims to capture both normal and
pathological dissociative experiences in adolescents. The A-DES has been cross-culturally
validated with positive results (e.g., Brunner, Parzer, Schuld, & Resch, 2000; Farrington, Waller, Smerden, & Faupel, 2001; Nilsson & Svedin, 2006; Shin, Jeong, & Chung, 2009; Soukup,
Papežová, Kuběna, & Mikolajová, 2010; Tolmunen et al., 2007; Yoshizumi, Hamada, Kaida, Katafumi, & Murase, 2010; Zoroglu, Sar, Tuzun, Tutkun, & Savas, 2002), and it is used worldwide to assess dissociative symptoms in adolescence. Given the relevance of the A-DES
cr ip
t
for the study of dissociation, it is important to provide researchers with further details about its
from the author of this study. Research with this translation has already shown that A-DES
us
scores are associated with post-traumatic symptoms and affect dysregulation (Caretti, Craparo, Ragonese, & Schimmenti, 2005; Caretti, Craparo, & Schimmenti, 2006; Schimmenti, Albasi,
M an
Lasorsa, Porcellini, & Granieri, 2005), and are predictive of substance misuse among adolescents (Caretti, Craparo, & Schimmenti, 2006). However, the psychometric properties of the A-DES in Italy were not fully explored until now. Therefore, the aim of the current study was to test the
ed
internal reliabilty and factor structure of the A-DES in a large non-clinical sample from Italy.
Participants
pt
Methods
ce
The study involved 1,806 high-school students (1,055 females, 58.4%; 751 males, 41.6%) recruited in 18 public schools specialized in different subjects (such as classical studies, teacher training, science, accountancy, languages, industrial engineering, tourism and hotel management)
Ac
Downloaded by [NUS National University of Singapore] at 16:01 06 November 2015
psychometric properties. The Italian translation of the A-DES was already available in 2005
from 6 cities (3 with over 1 million citizens, 3 with less than 200,000 citizens) in the North,
Center, and South of Italy. Participants ranged in age between 13 and 18 years (M=16.23; SD=1.60): 101 (5.6%) were 13 years old, 255 (14.1%) were 14 years old, 240 (13.3%) were 15
years old, 280 (15.5%) were 16 years old, 385 (21.3%) were 17 years old, and 545 (30.2%) were
18 years old. There was no significant association between gender and age of participants (χ2 (5) =1.20, p=.94, ns).
t
Procedures
cr ip
(English to Italian). A bilingual research assistant whose mother-tongue was English translated it
us
back to the original language (Italian to English), blind to the original version. Differences in the original and the back-translated versions were discussed until a consensus on cross-language
M an
equivalence was reached by joint agreement of both translators, with expert inputs further provided by other Italian scholars on dissociation (see Acknowledgements). In order to investigate the psychometric properties of the A-DES in Italy, the head teachers of 18 Italian high-schools were contacted. The objective of the study was described, and after ethical
ed
clearance they allowed researchers to administer the A-DES to their students. The students were informed about the nature of the study. Adult students signed an informed consent; parental
pt
informed consent was obtained from other students. Students completed the A-DES in their
ce
classrooms. This study was conducted in compliance with the author’s University Internal Review Board for psychological research. Measure
Ac
Downloaded by [NUS National University of Singapore] at 16:01 06 November 2015
The author of this study translated the A-DES from the original language to the second language
The Adolescent Dissociative Experiences Scale (A-DES; Armstrong et al., 1997) is a 30-item
self-report measure assessing the frequency of dissociative experiences in adolescents. The answers to the A-DES are marked on an 11-point scale ranging from 0 (never) to 10 (always).
The total A-DES score is the mean of all item scores. Thus, A-DES scores can range from 0 to 10, with higher scores indicating higher frequency of dissociative experiences. A mean score of 4 or above is usually considered an indicator of pathological dissociation, discriminating between
cr ip
t
adolescents with dissociative disorders and other adolescents (Armstrong et al., 1997). It was
imaginative involvement, amnesia, depersonalization/derealization, and passive influence).
us
However, studies on the factor structure of the A-DES showed that the 4-factor structure do not fit the data well in many samples, and often a single factor structure was preferred (Farrington et
M an
al. 2001; Nilsson & Svedin, 2006; Muris, Merckelbach, & Peeters, 2003; Shin et al., 2009). The A-DES has excellent internal consistency and test-retest stability, and it has proven to be valid across different cultural settings (Soukup et al., 2010). Given some exceptions (Nilsson & Svedin, 2006; Chabrol, Saint-Martin, Sejourné, Moyano, 2009; Yoshizumi et al., 2010), studies
ed
reported no gender or age differences in A-DES scores (Armstrong et al., 1997; Brunner et al.,
pt
2000; Farrington et al., 2001; Shin et al., 2009; Smith & Carlson, 1996; Zoroglu et al., 2002).
ce
Data analysis
Exploratory and confirmatory factor analyses were run to investigate the factor structure of the A-DES in the sample. Internal reliability and item-to-scale homogeneity of the A-DES were
Ac
Downloaded by [NUS National University of Singapore] at 16:01 06 November 2015
suggested that the A-DES theoretically comprises four symptom facets (absorption and
evaluated by calculating its Cronbach’s alpha coefficient, Spearman-Brown split-half reliability, and average inter-item correlations. Descriptive statistics were computed for the mean A-DES scores and for all the items the A-DES comprises. Differences in A-DES scores in relation to gender and age groups were tested through t-test and analysis of variance. A cluster analysis was
undertaken to classify participants into different groups according to their scores on A-DES items. A p value of 0.05 was set as the critical level for statistical significance.
t
Results
cr ip
derived 4-factor structure originally proposed for the A-DES (including absorption and
us
imaginative involvement, amnesia, depersonalization/derealization, and passive influence; see Armstrong et al., 1997) would adequately fit the data. The fit indices of the 4-factor structure
M an
were unsatisfactory (χ2=2849.75, df=399, χ2/df=7.14, SRMR=.046, CFI=.84, NNFI=.85, RMSEA=.058). Therefore, the structure of the A-DES was explored using principal component analysis. The sample size was excellent for this kind of analysis (Keyser-Meyer-Olkin=.96), and the population correlation matrix was not an identity matrix (Bartlett’s χ2 (435) = 17,720.66,
ed
p
