Standardization of user interfaces for lighting controls Bruce Nordman a, ⁎, Jessica Granderson a , Kelly Cunningham b a Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA b California Lighting Technology Center, 633 Pena Drive, Davis, California 95618, USA abstract article info Article history: Received 9 August 2011 Accepted 5 October 2011 Available online 10 October 2011 Keywords: Lighting controls User interfaces Standards Symbols Indicators Concepts Standardization of human-machine interfaces has proved beneficial in a number of technology areas. Light- ing control is a home and office technology that is of central importance in energy efficiency and could poten- tially benefit from standardization, which has proved beneficial in a number of technology domains. User interfaces enable and structure communication to and from devices, however when this communication is not understood, there is increasing loss of amenity to the user – in not getting the services they want – and potential compromise in efficiency. Standard user interfaces can help ensure the best possible outcome for communication. This paper presents a summary of initial research on content for a global standard for lighting control user interfaces. A review of potentially relevant industry standards confirmed that there is no existing standard that covers this topic area, though many standards are related, including those covering symbols, indica- tors/actuators, generic user interface issues, accessibility, user interface content common to other energy concerns, and terminology. We surveyed many existing products, from simple switches, to those with many buttons, to those using graphic display technology. We describe a classification scheme for the entire ‘form’ of the control, catalogued the use of specific “elements” in the interfaces, and extracted topics (“con- cepts”) that embody meaning and are represented in collections of interface elements. Finally, we consider plausible paths forward to creating content suitable for a global standard. © 2011 Elsevier B.V. All rights reserved. 1. Introduction This paper presents an investigation of the role of standardization in the design of user interfaces for lighting control. Standardization of the elements and conventions in human-machine interfaces has proved successful in increasing user understanding and reducing op- erational errors in a number of areas [1], including automobile con- trols and alphanumeric assignments for telephone keypads [2,3]. Lighting accounts for nearly 8% total national energy use, making it an important yet under-studied home and office technology that in- tersects energy efficiency, interfaces, and standardization. In spite of the link between user understanding, correct opera- tions, and device energy consumption, lighting controls are often no- toriously difficult to decipher. For example, it is common to find operational instruction sheets posted near or on switches, as in Fig. 1 below. To-date the evidence that lighting control user interfaces would benefit from improved usability is largely anecdotal, rooted in building occupants’ shared experiences, or addressed in Internet blogs focused on design [4–7]. References to the complexity of light- ing control user interfaces, and the resulting challenges for users can be found in the literature [8,9], but comprehensive usability stud- ies specific to the evaluation of lighting control interfaces have not been documented in the public domain [10]. Across the landscape of commercial and residential lighting con- trols, one often encounters interfaces that look the same but are bound to control systems with very different functionality, and there- fore effect a wide diversity of system responses. The converse is also true: one often encounters different interface elements that effect precisely the same response or functionality. These concepts are illus- trated in Fig. 2, which shows from right to left, interfaces that comprise: • A single slider, where actuation upward is to brighten, and actua- tion downward is to dim. • Arrow buttons, again where actuation upward is to brighten, and actuation downward is to dim; the buttons are combined with LEDs to indicate the brightness level. • No elements to suggest dimming capability or brightness level. • A light bulb icon paired with an ‘increase’ symbol and indicator light, where actuation to the right brightens and actuation to the left dims. Computer Standards & Interfaces 34 (2012) 273–279 Abbreviations: LED, Light Emitting Diode; HVAC, Heating, Ventilation and Air Con- ditioning; IEC, International Electrotechnical Commission; ISO, International Organiza- tion for Standardization; CIE, The International Commission on Illumination; SAE, Society for Automotive Engineers International; IEANA, Illuminating Engineering Soci- ety of North America; NEMA, National Electrical Manufacturers Association. ⁎ Corresponding author. Tel.: + 1 510 486 7089. E-mail addresses: bnordman@lbl.gov (B. Nordman), jgranderson@lbl.gov (J. Granderson), kcunning@ucdavis.edu (K. Cunningham). 0920-5489/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.csi.2011.10.003 Contents lists available at SciVerse ScienceDirect Computer Standards & Interfaces journal homepage: www.elsevier.com/locate/csi