Despite their ubiquitous presence in the centre of the modern city, micro-scale outdoor environments like plazas and squares have remained almost totally free of any intensive research to suggest to designers: what physical make-up would render them perceptually good, what form and configuration would sustain public use and what would repel. This empirical study uses concepts and methods of psychological sciences to establish relationships between the visual quality and physical configuration of plazas and human use and feelings within them that may serve to suggest guidelines for their designs. The phenomenological impacts of several open spaces of the central business district of Vancouver, British Columbia, on the psychological states of people were measured through people's ratings on verbal psychological scales within these environments. The extent and nature of use of these spaces were observed over a period of seven months. The number of persons using these spaces, their overt activities, postures, demographic characteristics as well as physical distribution across various facilities and parts thereof were recorded at different points of time through time lapse photography as well as visual observation supported by behavioral mapping technique. Significant differences were found among nine plazas in terms of their observed popularity as well as verbally measured pleasantness and diversity in the visual environments. Perceived diversity in the visual environment of plazas accounted for 60% of their pleasantness and popularity. Season, weather condition, time of the day and vocational background of respondents (i.e. designer or nondesigner) had insignificant effects on the perceptual and emotional responses of people across these plazas. Across plazas located in the interior of the downtown, significant positive relationships were found between their verbally measured pleasantness and diversity in the environment and the variety (Average uncertainty; Re: Information Theory) as well as density in their internal furnishing elements. Furthermore, respondents' comments indicated that the amount and variety in their internal furnishing, the presence or absence of focal attractions and the colour of their pavements and enclosing surfaces were the most popular reasons for people's pleasure-displeasure and perception of diversity (or the lack of it) across these spaces. Waterfront plazas were more pleasant, more diverse and more popular, particularly in Summer, than most plazas in the interior of the downtown. Across these plazas, however, the surrounding view rather than the internal landscape was the determining factor in peoples pleasure and perception of diversity. Population distribution within plazas suggested the greater efficiency of small-sized, densely furnished spaces with articulated edges and limited and defined pedestrian circulation channels than extensive areas and expansive pavements. Activities tended to accumulate on artifacts, along edges, around focal elements and close to other activities while open and undefined paved areas and facilities remote from the area of population concentration, view or movement channels were rarely used. Pedestrian circulations took place along shortest routes between streets and buildings. Solitary persons and small groups were the predominant users of plazas. The observed use of furniture elements illustrated the greater efficiency of articulated shapes and arrangements that intrinsically provided defined territories and orientational choice for small-group users than non-articulated expansive forms and straight linear constructions of benches, railings, pools' and planters' edges. Diverse configurations, furthermore, provided niches for users of different demographic nature and supported their co-existence within plazas. The effects of extraneous factors like time, weather condition, season and landuse surrounding plazas on the use of these spaces were also analyzed. The findings indicate that subtle difference in the physical environments across these small outdoors may significantly alter people's feelings within them as well as the nature-and extent of use of these spaces. Specifically, diversity in their visual contents and articulation in their spatial configuration and facility planning are essential ingredients to render plazas pleasant, popular as well as supportive of personal and behavioral freedom of their users. / Land and Food Systems, Faculty of / Graduate