In order to analyze the heating malfunction case in this study, a framework which addresses the domains of both HCI and infrastructure is necessary. The user control which shapes the user experience and, conversely, a part of the user experience, should be considered in the use context, the smart home infrastructure. In order to conduct a holistic research which combines those two different domains, the framework of Edwards et al. [14] will be employed in the analysis and the discussion of the case. Their framework addresses
infrastructure problems in HCI, focusing on the dependency of HCI on the infrastructure and the tension between them.
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3.3.1 Development of the framework
The framework of Edward et al. [14] is built upon the previous work by Brand [5] and Rodden and Benford [36]. In the framework by Brand there are six layers which comprise a building; listed from outside to inside, Site, Skin, Structure, Services, Space Plan and Stuff.
Site is the geographical location and it lasts longer than buildings. Structure refers to the building itself, the foundation and load-bearing elements of the building. Skin is the exterior surfaces of the buildings. What makes the building work are the Services, such as
communications, wiring and plumbing, which are embedded in the Structure. The interior layout, where walls, ceilings floors and doors go, is affected by the Space Plan. All the artifacts that occupy the space, for instance furniture, appliances and decorations, are referred to as Stuff. All the layers have different rates of change which might thus risk the building to be torn apart as it evolves.
The layers suggested by Brand provide Rodden and Benford with a basis for the analysis of domestic environments, regarding the development of interactive digital devices for domestic use. In their analysis, they maintain that it is important to expand the scope of the research so as to study the real context where the interactive domestic devices are to be placed. Chetty et al. [7] assert that Rodden and Benford have made home infrastructure and interactions between the technical and physical visible by outlining diverse stakeholders involved and activities related to each layer.
3.3.2 The layers of engagement in infrastructure
Similar to the work by Rodden and Benford [36], Edwards et al. [14] also adopt a layered analysis built upon the work by Brand, in order to address the infrastructure problems in HCI.
Edwards et al. present four new layers of infrastructure and outline on each layer the process managed and the activities required for addressing the identified infrastructure challenges, in order to contribute to design for positive user experiences. The four layers are as follows:
Surface approach has its focus on superficial layers which users interact with and face the most. It attempts to protect users from challenges caused by infrastructure.
Interface approach is concerned with the applications which support the infrastructure. It aims to improve the mapping between conceptual models of users and system functions.
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Intermediate approach attempts to provide new flexible infrastructure technologies, to deliver an improved user experience by designing a novel type of applications. This is a more
proactive approach compared to surface and interface layer, as it seeks to make changes closer to the infrastructure. However, their capabilities are restricted by even more fundamental infrastructure layers.
Deep approach endeavors to affect the infrastructure itself, which requires the engagement of systems specialists who design infrastructure. It is a more fundamental approach compared to others presented above, as it can contribute to overcoming infrastructure problems in HCI.
Boundary objects, which will be presented in the following section, are proposed as a concept to employ for cooperation between multidisciplinary groups on the deep level
Figure 3 illustrates how the four approaches by Edwards et al. are related to the shearing layers by Brand. The four layers (left in figure 3) do not exactly overlap with Brand’s layers (right in figure 3), as the four approaches are oriented towards the digital infrastructure. The relation, for instance between the intermediate and deep layer and outer layers, skin, structure and site, is not clear. However, the illustration might help to visualize connections between two sets of layers.
Figure 3. The mapping between the layers by Brand [5] and the approaches by Edwards et al. [14]
Boundary object
Boundary objects are objects flexibly interpreted to adapt to the local needs but robust enough to maintain the identity which would commonly be understood by various
communities. The term Boundary objects was coined by Star [4] and is the concept suggested
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as one of the concrete solutions when addressing the infrastructure problem on the deep layer in the framework. The boundary object is useful at the organizational level, such as the deep layer, where the experts from multidisciplinary groups need to cooperate. Boundary objects allow different groups to work together without consensus because they can be used to balance and manage different categories and meanings when there are divergent viewpoints.
In other words, it is important to create and manage boundary objects in order to build coherence among diverse communities of practice. They are the basis for conversation and action and become a communicative device across intersecting communities.
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