Abstract
— From a theoretical perspective the effect of hospital treatment depends on how the ward milieu is perceived by the patients. An objection against the measurement of patient perceptions has been that lack of reliability would invalidate the assessment. To investigate this objection 49 inpatient wards were evaluated with the Ward Atmosphere Scale (WAS). The real ward (WAS-R) scores proved to have acceptable reliability both for patients and for staff. For the ideal ward (WAS-I) scores the reliability was mostly unacceptable for both groups. The content validity of the WAS subscales was found to be acceptable by a group of experienced psychiatrists. Criterion oriented and construct validity were also acceptable, even if the WAS lacks some seemingly important variables. A comparison of WAS scores from four different countries indicated that the WAS has excellent cross-cultural properties. The WAS seems to measure fairly stable aspects of the atmosphere. The WAS scores proved to be fairly stable, even on wards where patients and staff desired considerable changes.