Photographic comparison: a method for qualitative outdoor thermal perception surveys

Abstract

This article addresses the use of photographic comparison as a complementary visual appraisal method in an outdoor thermal perception survey. This survey was carried out during a Ph.D. research exploring how materials and vegetation influence thermal comfort in outdoor public spaces. Objective and subjective thermal perception parameters were combined and quantitative and qualitative research methods were used. The quantitative methods included microclimatic measurements, whilst the qualitative methods comprised observations and spatially localised interviews based on a questionnaire and the photographic comparison. This article explores how such visual research method allowed triangulating findings of this field survey. Three non-edited photographs of outdoor public spaces, under similar summer meteorological conditions but with contrasting spatial features, were shown to respondents to the questionnaire. The photographs depicted undisclosed locations for preventing biased emotional appreciations. Respondents were asked to select the potentially most comfortable and uncomfortable environments depicted. The choice of photographs matched the previous answers on the thermal sensation and evaluation judgement scales. Hence, we discuss the way the visual interpretations by respondents allowed the triangulation of in situ thermal perception data. The extent to which thermal comfort can be interpreted from thermal environments depicted in photographs containing clear visual signs is further discussed. The article concludes on how such a visual appraisal method can be valuable for enriching future qualitative outdoor thermal perception surveys with subjective interpretation of visual data.

A review of assessment methods for the urban environment and its energy sustainability to guarantee climate adaptation of future cities

“…Also, the thermophysical properties of the facades of the buildings play a significant role in the urban comfort, since they can reflect, or absorb, the solar radiation, consequently directly impacting the city liveability. Extending the scopes of the debate, the city form itself impacts not only buildings energy demand and thermal comfort; they affect our perception of the space and human cognition [72], [73].…”

Behavioural Perspectives of Outdoor Thermal Comfort in Urban Areas: A Critical Review

“…Drawing on this theory, Cortesão et al (2018) adopted a framework to study the processes of the visual interpretation of built and vegetated materials in relation to people's outdoor thermal perceptions in Porto, Portugal [34]. The visual interpretation was made by participants using a photographic comparison of environmental signs in three outdoor spaces.…”

More than meets the eye : a critical semiotic analysis of landscape design visualizations

“…Design representations can be defined as complex sign-systems that contain a large number of signs within themselves (Raaphorst et al 2018). Different sign components, i.e.…”

“…Apart from the participatory planning and design processes of MFFD projects many cases could benefit from the critical visual research approach presented in this thesis. For example, the visual content analysis of Chapter 3 has been applied to a study of the use of photographic comparison to triangulate qualitative outdoor thermal perception surveys (Cortesão et al 2018). This study suggests that the identification of particular combinations of visual signs, which signify degrees of outdoor thermal comfort, can help (urban) designers to conduct more valid qualitative inquiries and, in turn, communicate the microclimatic conditions of their designs more effectively.…”

“…representation has three main communicative elements: its medium possesses a level of interactivity, its visual mode provides a degree of readability, and its content is arranged in such a way it provides a certain validity (Figure 5.1) (Raaphorst et al 2018). Design representations are interpreted by different audiences in different ways because every interpreter has a particular 'interpretive habit' (Raaphorst 2018). These habits consist of discursive networks, or strings of connotations, that are triggered by a design representation or particular aspects of that representation.…”