THE SUBJECTIVE MEANING OF GOOD SLEEP, AN INTRAINDIVIDUAL APPROACH USING THE KAROLINSKA SLEEP DIARY

The present experiment used an intraindividual design to investigate t he meaning and measurement of ''good sleep.'' Each of 16 subjects slep t in an isolation unit according to a schedule (15 sleeps) designed to give variable quality of sleep. Self-rated sleep measures (from the K arolinska Sleep Diary) were obtained after each sleep and subjected to intraindividual regression analyses across time. Most subjective slee p measures showed a strong covariation across conditions. Subjective q uality of sleep mainly involved variables of sleep continuity, in part icular, perceived calmness of sleep and sleep efficiency. ''Sleep qual ity,'' ''calm sleep,'' ''ease of falling asleep,'' and ability to ''sl eep throughout'' the time allotted strongly covaried and an index of s leep quality. Self-rated ease of awakening deviated from the general p attern and was associated with poor sleep quality. So was reported dre aming (related to awakenings). It was concluded that most subjective s leep measures tend to covary across conditions and that ''good sleep'' is mainly a question of sleep continuity.