Sleep Related Questionnaires

Stanford Sleepiness Scale (SSS)

Name of questionnaire Stanford Sleepiness Scale (SSS)
Type of questionnaire-description Self-rating scale which is used to quantify progressive steps in sleepiness at a certain point in time.
Number of items Not applicable
Number of domains/categories 1
Name of categories/domains   Degree of sleepiness
Scaling of items Seven –point Likert-type scale has descriptors ranging from “feeling active, vital alert, or wide awake” (score = 1) to “no longer fighting sleep, sleep onset soon
and having dream-like thoughts” (score = 7)
Scoring available: with permission or free Free
Scoring test-retest reliability 0.88
Scoring Internal consistency Not available
Validity Validity of mean SSS using the Wilkinson addition and vigilance tests was reported at correlation of 0.68
Language English 
Translations in other languages (if yes, then list the languages) Not applicable
Developer name E. Hoddes, V. Zarcone, H. Smythe, R. Phillips, W. C. Dement
Developer contact information William C. Dement, M.D., Ph.D.
Professor of Psychiatry and Sleep Medicine
Department of Psychiatry and Behavioral Sciences
Stanford University School of Medicine
1050A Arastradero Rd.
Palo Alto, CA 94304
Ph: 650-723-6320
Fax: 650-723-8134
Availability of questionnaire: needs permission from developer, cost or freely available Freely available
References (original publication) Quantification of Sleepiness: A New Approach.Psychophysiology
Volume 10, Issue 4, pages 431–436, July 1973
Limitations Questionable reliability in chronic sleep deprivation, cumulative  partial sleep deprivation and narcoleptics  
Link to the questionnaire (if available) http://www.stanford.edu/~dement/sss.html
Other comments It can be administered many times per day, correlates with standard measures of performance, and reflects the effects of sleep loss.