OBJECTIVE: To validate the Portuguese version of the Puberty and Phase Preference Scale, designed by Carskadon, Vieira and Acebo in 1993, which investigates the waking and sleeping time of adolescents and their feelings related to these habits, in order to classify them as morning or evening people. METHODS: The study included 144 elementary school students, 86 boys and 58 girls, aged 13.2±1.6 years-old. The construct was validated by a predictive criterion. The scale of the circadian rhythm was applied to the students in the classroom. One month later, for seven consecutive days, the students were asked to answer another questionnaire regarding the time they slept the day before and when they woke up on the next day. To evaluate the evidence of criterion validity, one-way variance analysis followed by the least significant difference post-hoc test were applied. RESULTS: The psychometric properties of the scale were satisfactory. The analysis of internal consistency by Cronbach's Alpha was 0.791. CONCLUSIONS: The results indicated good consistency and validity of the allocation preferences in the sleep/wake cycle. All indexes were significant and directed to the time expected, pointing out the scale validity.
circadian rhythm; validation; sleep; wake
