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Visual Access/Exposure Analysis
Purpose: This analysis method is designed to identify the physical characteristics of a space that contribute or hinder privacy. It is based on theory and methods developed by Benedikt and Archea. Analyzing patterns of visual access and exposure reveals the relationship between the form of space and privacy behavior.
Definitions:
Privacy is access to information about the self. It involves two or more individuals in dyadic relationships. Each person has expectancies for access and exposure that are established by the culture, social unit and personality.
Visual access refers to the degree to which information can be obtained from a point through unobstructed visual surveillance.
Visual exposure is the degree to which an individual is visible from other destinations in the space.
An Isovist is a field of information that is visible from a point in space (yellow area in diagram)..
Characteristics of information flows:
- walls and objects in the visual field block visual access and exposure
- since people move through space, those patterns unfold as our vantage point changes
- we can control information flows by situating ourselves at locations that optimize our intentions
- the conditions evident in an environment can be considered 'traces" of the design intent, e.g. lack of access means that the designers intended to block information flows (i.e. communication).
- misfits occur between environments and the participants' intentions
Patterns of privacy to consider in the analysis:
- high levels of visual access provide high levels of information about events in the organization and high levels of awareness of resources
- accountability for behavior is greatest in places with high levels of exposure
- low levels of visual access restrict the flow of information in an organization
- low levels of visual exposure increase the potential for freedom of action but also reduce accountability
- relatively equal levels of access and exposure balance accountability with autonomy as well as awareness with confidentiality
Analysis steps:
- select a behavior setting or settings to study
- identify critical information flows, e.g. where social control, awareness of opportunities, communication, autonomy of actions, etc. are important for the inhabitants
- map key visual access patterns from appropriate locations using isovists; consider the likely pattern of visual search - field of view
- map the visual exposure to the locations using isovists
- compare patterns of access and exposure for different locations and different building users
- analyze the balance of exposure and access at important locations and times (e.g. different times of day, when doors are open or closed, etc.).
- analyze the impact of movement through the space and the unfolding of access and exposure, e.g. how much movement is necessary to get needed information, how the pattern of exposure is affected by movement.
Documentation:
- plan with notations of key observed and reported behaviors
- map(s) of important visual exposure conditions
- map(s) of important visual access conditions
- descriptions of the congruence between privacy desired and privacy obtained
- explanations of how the structure of space affects privacy behavior
Note: Statistics can be computed to compare degrees of access and exposure as well as ratios (e.g. reciprocity). Comparisons between locations are particularly useful in understanding how people adapt to the building. Photographs or sketches can be helpful in communication as well.
Complete a visual access/exposure analysis for your assigned case study building. Prepare 2-5 overhead transparencies showing your findings and conclusions.
Be prepared to discuss the following in class:
- Does the building communicate appropriate information about the activities that take place in the department?
- Is there a high degree of access or exposure? Does it differ from time to time and how?
- How does the building design support/hinder the visitor's understanding of the organization?