Herbert M, Johns M W, Doré C
Br J Med Psychol. 1976 Dec;49(4):373-9. doi: 10.1111/j.2044-8341.1976.tb02388.x.
A series of 18 visual analogue scales was used to report the subjective feelings of 38 healthy subjects on 732 occasions during experiments concerned with the quality of sleep. Factor analysis of scores from these scales, both for all subjects combined and within each of four subjects separately, yielded two factors consistently -- 'alertness' and 'tranquillity'. Scores derived from the first factor indicated that, in the laboratory setting levels of immediately after waking in the morning were reduced, in relation to those before falling asleep on the previous night.
在一项关于睡眠质量的实验中，使用了一系列18个视觉模拟量表来报告38名健康受试者在732次情况下的主观感受。对这些量表的得分进行因素分析，无论是对所有受试者综合分析还是对四个受试者分别进行分析，都始终得出两个因素——“警觉性”和“宁静感”。从第一个因素得出的分数表明，在实验室环境中，早晨醒来后的水平相对于前一晚入睡时有所降低。
