1. Affordance, Ability, and Context:
Issues of Human-Computer Interaction and Computer-Mediated Human Interactions in Architectural Design
Hamid Abdirad
Dec 8, 2015

2. Background
Tzonis and White (2012), early developments in design computing were stimulated by the analytical paradigm offered by Chermayeff and Alexander (1963).
…“design is a general-purpose solving method independent of the particularities of a given project,” and
…“design problems have become too complex to be solved by intuition or tradition any more, but they can always be solved through the computer” (Tzonis and White 2012, 2-3).
BUT …
Scholars realized architectural design requires knowledge-based reasoning and intelligence, characteristic that are missing in most design computing developments.

3. Background
Graphic proposals and architectural representations serve as working documents for architects and as communication mediums for all stakeholders.
Architectural knowledge and design reasoning are naturally expressed graphically in this practice.
Tzonis and White (2012, 16-17): how knowledge is best represented in a computer to support reasoning of the kind in which architects engage.
This paper investigates how existing developments in computer-based modeling and representation have shortcomings in supporting architectural reasoning.

4. Affordance, Ability, Situation
The perceived and actual properties of an object that determine how it could possibly be used.
Ability:
is the contribution of the person in the interaction.
Situation:
Level of affordance or ability depends on attributes, functions, and characteristics of the environment and those of the agent.
Situations can impact affordances and abilities by putting constraints. In some cases, the agent should attune to constraints, meaning that to know how to do/perceive things when constraints exist.

5. Bias in CAD/BIM: Impact on Users
Design is a flexible process that requires non-linear development of ideas in order to be creative, while current computing platforms are not flexible enough to adapt to the provisional nature of design.
Bias of CAD tools:
when the mental conceptions, relationships, and required mental actions for creating design elements are not matching to representations and operations afforded by CAD and computational tools.

6. Bias in CAD/BIM: Impact on Users
Example: “translation” methods required for translating components of a design concept to CAD components are different in different platforms, and this would result in unevenness of processes and operations required to work with different CAD platforms.

7. Bias in CAD/BIM: Impact on Users
Example 2: some CAD platforms require designers to shift to a different (and maybe non-graphical) representation mode in order to create a non-standard design. This “representation shift” becomes problematic when CAD technologies evolve and technicians need to migrate to new platforms with different capabilities and representation modes.

8. Bias in CAD/BIM: Impact on Stakeholders
Example 1: Providing “False Affordance” in a public library design competition; designers used image processing software to modify color, saturation, contrast, number and locations of human figures, cars, trees, and manipulated lighting and weather effects to adjust the graphics, although one image as a reference for representation was provided by the public client

9. Bias in CAD/BIM: Impact on Stakeholders
Gomez and Haskins 2012

10. Bias in CAD/BIM: Impact on Stakeholders
Example 2: Providing “False Affordance”
“Policies could be breached and all would be forgiven for the joy this Babylonian utopia would bring […] the reality is more like a couple of rockeries and a few trees in pots.” Wainwright (2015)

11. Bias in CAD/BIM: Impact on Stakeholders
Example 2: Providing “False Affordance”
“Policies could be breached and all would be forgiven for the joy this Babylonian utopia would bring […] the reality is more like a couple of rockeries and a few trees in pots.” Wainwright (2015)

12. Conclusion Design computing platforms:
Have shortcomings in providing sufficient affordances.
Some affordances they offer have conflicts mental conceptions, relationships, and required mental actions for creating design elements.
They may offer false affordances.

13. Questions?