Matches, Mismatches, and Methods: Multiple-View Workflows for Energy Portfolio Analysis

Abstract

The energy performance of large building portfolios is challenging to analyze and monitor, as current analysis tools are not scalable or they present derived and aggregated data at too coarse of a level. We conducted a visualization design study, beginning with a thorough work domain analysis and a characterization of data and task abstractions. We describe generalizable visual encoding design choices for time-oriented data framed in terms of matches and mismatches, as well as considerations for workflow design. Our designs address several research questions pertaining to scalability, view coordination, and the inappropriateness of line charts for derived and aggregated data due to a combination of data semantics and domain convention. We also present guidelines relating to familiarity and trust, as well as methodological considerations for visualization design studies. Our designs were adopted by our collaborators and incorporated into the design of an energy analysis software application that will be deployed to tens of thousands of energy workers in their client base.

Assessing 2D and 3D Heatmaps for Comparative Analysis

“…The aggregation views were added to make a fair comparison to state-of-the-art methods for comparative analysis [53]. We used a color scale (blue-white-red) that is frequently deployed for comparative tasks of heatmaps with negative values [46,28,7,12]. In the VR condition the visualization was attached to a wall standing in the virtual environment and participants were able to move in the virtual space, whereas in the Screen condition the 2D visualization was centered on the screen and no motion interactions were provided.…”

Chronodes

“…This challenge is customary in healthcare analysis: apart from needing to understand the relationships between a patient’s various physiological records, analysts must do the same between thousands of patients on end [3]. Principally, Aigner et al [1] and Brehmer et al [6] provide a series of typologies and guidelines for visualizing timeline data according to a variety of data types and representational criteria. Meanwhile, approaches to “multifocus” timeline visualization [38, 42] compliment such techniques by enabling users to select multiple segments of time from timeline visualizations, which can then be displayed in a consolidated format and used to find similar patterns [43].…”

“…However, we represent frequent event sequences as kebabs to emphasize the distinction between, on the one hand, chronological event sequences and, on the other, continuous event data that is not averaged across multiple timelines, as reflected in the Event Orchestra . In this way, the kebabs provide a consistent visual iconography to represent event sequences that are averaged and represented on relative—as opposed to absolute—time scales [6]. More generally, the kebab representation on the Sequence Stage helps to differentiate frequent event sequences from continuous events in the Event Orchestra .…”

Human-Building Interaction: When the Machine Becomes a Building

“…Schwartz et al [63] present a critical investigation into user perception of energy feedback. Such visualizations, together with data analysis methods, may also prove useful for other stakeholders such as expert engineers or building facility managers [13,49,53].…”

“…Within a limited time span (up to 20 minutes), they were able to spot various behaviours specific to the building which were not possible to infer from raw data, such as spotting malfunction and identifying non-trivial relations between measured variables [9] (see Figure 7). A similar example addresses energy portfolio analysis [13]. In these cases, the conjunction of interactive technologies in a building design or industry context qualifies for the strong definition of HBI.…”