Karolinska Sleepiness Scale.

KSS

What it measures

Momentary subjective sleepiness or alertness at a given point in time

Length and format

1 item. single 9-point verbally anchored scale (1 extremely alert - 5 neither alert nor sleepy - 9 very sleepy, great effort to keep awake, fighting sleep) (self-report questionnaire)

Language versions

20+ langs; used internationally in sleep, fatigue, shift-work, aviation and driver-safety research (approx)

Normative data

No normative data held in our reference library for this instrument. That is a statement about our library, not about the published literature.

Licence

public-domain / open

Licence classification is a research judgement by the catalogue’s authors, not legal advice, and it can be out of date. Confirm terms with the copyright holder or publisher before using an instrument, especially for commercial use.

Reference

Akerstedt, T., & Gillberg, M. (1990). Subjective and objective sleepiness in the active individual. International Journal of Neuroscience, 52(1-2), 29-37.