Psychometric properties of the reduced Horne and Ostberg questionnaire

The purpose of the present study was to begin the process of establishing p sychometric soundness of the reduced Horne and Ostberg questionnaire (rH&O, Adan & Almirall (1991). Horne and Ostberg morningness-eveningness question naire: a reduced scale. Personality and Individual Differences, 12, 241-253 .). In the first stage of the study a total of 1882 students from the Unive rsity of North Dakota were administered the original H&O questionnaire (Hor ne & Ostberg (1976). A self-assessment questionnaire to determine morningne ss-eveningness in human circadian rhythms. International Journal of Chronob iology, 4, 97-110. 19-items). Five items that constitute the rH&O were extr acted from the original 19 items questionnaire and the relationship between the total scores of both questionnaires, and between the circadian types d etermined by H&O and rH&O was measured by computing appropriate correlation coefficients. In the second stage of the study the original H&O questionna ire and the rH&O (5-items) questionnaire were administered to another group of college students (n = 150). The results from both parts of the present study indicate that the rH&O has adequate inter-item correlations as well a s high coefficient alpha. Furthermore, the rH&O questionnaire is sufficient ly sensitive with respect to the results of the original H&O questionnaire and it reliably classifies research participants across the "morningness-ev eningness" dimension. Working with the rH&O could save both the researchers and the participants time and effort, especially if large samples of popul ations are to be studied. Conclusions and limitations are discussed as well as the directions for future studies. (C) 2000 Elsevier Science Ltd. All r ights reserved.