Exploring former interaction qualities for tomorrow s control room design

This paper addresses the lack of interaction qualities in control rooms by investigating the potential use of Hybrid Surfaces. As an emerging trend with strong real-world references, they offer the combination of both, the qualities of physical interaction and the potentials of the digital world. To determine their applicability in the given context we applied the theoretical framework ‘Reality-Based Interaction’ in line with an expert focus group. As the primal finding tangible forms have aroused great interest as they embody the feature to express ongoing processes states and allow multimodal interaction. 1 Background and Motivation Control rooms are facilities that serve as operations centers to monitor and control complex processes, e.g. in power plants or industrial production plants. One essential task in operating control rooms consists in the manipulation of process variables, which represent the physical state of the supervised process. According interfaces have to provide an adequate presentation of these ongoing processes. In practice, however, the actual process does not coincide with the real world process (Herczeg 2003). As a result, the interface may therefore not provide an adequate mental model for the operator (Wickens 2004). Hence, a crucial factor in control room interfaces is the ability to express the underlying process sufficiently. Control rooms and interfaces have changed over time. Before digital technology found its way into the domain, processes were monitored by electromagnetic displays and variables were manipulated by electro-mechanic control actuators. These interfaces provided multimodal feedback such as inertia and sound, e.g. when an actuator clicks into place. In the course of digitization these physical artifacts were replaced by virtual control elements that are operated through desktop computers. However this kind of interaction does not provide the qualities of the multimodal interfaces, nor does it utilize associated body skills. Hence, operators no longer experience process changes on a holistic-cognitive base. This circumstance is often linked with an incomplete mental model (e.g. Herczeg 2003) and the lack of situation Exploring former interaction qualities for tomorrow’s control room design 2 awareness (Wickens 2004) which both are of vital importance for system maintenance and appropriate reactions on safety-critical events. 2 Reality-based Interaction Styles on Hybrid Surfaces By looking at the history of control rooms we identify a relationship between power and reality as stated by Jacob et al. (2008): While digitization gave control rooms more processing power it also set off a drift from former interaction qualities that were strongly related to real-world phenomena. “Reality-Based Interaction” (RBI) (Jacob et al. 2008) discusses these opposing dimensions in the light of user interfaces and provides respective design implications. RBI presumes that building interaction upon informal real-world knowledge which is summarized by four RBI themes reduces the required mental efforts: “Naïve Physics”(NP) assumes that humans have a common understanding of fundamental physical principles such as gravity, “Body Awareness & Skills” (BAS) addresses the humans’ motor skills, “Environment Awareness & Skills” (EAS) points out that human interaction occurs within the individual’s structural environment while “Social Awareness & Skills”(SAS) highlights that interaction naturally takes place within a social context. At the same time RBI suggests that building interaction exclusively on realism may limit the power of an interface. Thus, desired interface qualities can only be achieved by adding digital functionality. Regarding former interaction qualities and today’s requirements in control room design we consider Hybrid (Interactive) Surfaces as defined by Kirk et al. (2009) as a promising candidate to achieve interaction styles that combine real-world qualities (such as multisensory feedback) with today’s digital potentials. Furthermore, Hybrid Surfaces offer a wide design space where virtual and physical expression may be combined in various ways. For later discussion we defined two major interaction styles. Hancock et al. (2009) refer to the ends of the continuum as direct-touch and tangible user interfaces (TUIs). Both forms enable “direct manipulation” as defined by Shneiderman (1983) and avail themselves of real-world knowledge. Direct-touch interfaces express real-world objects and their properties metaphorically. Thus, they are commonly attributed to “Natural User Interfaces”. With respect to the directness of manipulation, direct-touch interfaces can be considered to be more direct than mouse and keyboard scenarios (Jacob et al. 2008) as no mediating device is necessary for the manipulation of the visual model. TUIs primarily base on physical expression due to their materialistic properties. Unlike direct-touch interfaces they do not mimic Naïve Physics but instantiate them. Numerous qualities are attributed to TUIs of which intuitiveness (Ishii & Ullmer 1997) may be the most preeminent in terms of affordances. Regarding their physical properties Klemmer et al. (2006) found prove that tangible interaction facilitates motor memory. In practice TUIs are usually composed in a way that includes direct-touch features. Hence, the balance of both spheres plays a major role in interface design. For this reason we distinguish “active tangibles” that receive and express the state of a process variable and “passive tangibles” that do not embody such functionality. While Inami et al. (2010) highlight the motor property of active tangibles (such as “tangible bots” by Pedersen & Hornbæk (2011)), we propose that activeness should refer to the ability to retrieve and express any kind of information that is relevant for the underlying model or variable. Exploring former interaction qualities for tomorrow’s control room design 3