The purpose of this article is to explore whether spatial definition can affect the perceptual evaluations of users in highly dense conditions. The particular spatial definition Studied in this research was the relationship between circulation axes and seating areas of a waiting hall. In crowded public interiors, it is generally assumed that users feel less comfortable and less safe. As suggested in this work, the disturbance is much higher even where there are less-defined boundaries (where people pass through from different directions) and the space is more likely to be perceived negatively. To research this, a Study was carried out in three waiting halls of a large polyclinic building: a clinic waiting hall, a pharmacy waiting hall, and an X-ray waiting hall, spatially designed different from each other. Results from 240 patients showed that the least identifiable waiting hall design was perceived the most negatively. The effect of gender on performance appraisal task was also examined. Compared to females, male users perceived the space more positively than female users. (c) 2006 Elsevier Ltd. All rights reserved.