This paper examines the psychometric quality of the Early/Late Preferences Scale (PS) relative to that of the Composite Morningness Scale (CS). Questionnaires were completed by 670 undergraduate students aged 16-37 years (mean 22.5), of whom 64% were female. Both scales displayed satisfactory inter-item correlations and similar total mean scores to those reported previously, although the CS had higher variability. Principal axis factor analysis produced single-factor solutions for both scales, although loadings for Items 7 and 9 on the PS were low. Internal consistencies for both scales were good (PS = 0.86, CS = 0.90) with only a small improvement achieved by deleting Items 7 and 9 from the PS. Test-retest reliability over 11 weeks was good for both scales (PS = 0.92, CS = 0.89). Differences between morning, evening and intermediate groups in self-rated alertness at different times of day, and significant correlations with other indices of morning-evening orientation, provided evidence of validity for both scales. These results indicate that PS is psychometrically comparable with CS. In view of its simpler format and lower cultural specificity, PS may be considered a preferable measure for most applications.

Item Type:	Refereed Article
Research Division:	Commerce, Management, Tourism and Services
Research Group:	Strategy, management and organisational behaviour
Research Field:	Organisational behaviour
Objective Division:	Law, Politics and Community Services
Objective Group:	Work and labour market
Objective Field:	Work and labour market not elsewhere classified
UTAS Author:	Bohle, P (Professor Philip Bohle)
ID Code:	138827
Year Published:	2001
Web of Science® Times Cited:	41
Deposited By:	TSBE
Deposited On:	2020-05-01
Last Modified:	2020-05-01
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