Standardization of Light-Emitting Diode Feedback on Metered Solar Home Systems Used in Rift Valley, Kenya.

Abstract

Light-Emitting Diodes (LEDs) are used in a variety of devices ranging from watches to solar home systems, as status indicators or communicative tools. They are typically designed to produce light in different colors and intensities. However, the communicative output varies across devices of similar or different functions. This variation and the sense that there is a wide array of expressions that can be employed, makes it hard for users of the devices to deduce the feedback easily. This research aimed to highlight usability challenges associated with interaction with non-standardized LEDs on metered solar home systems and address this gap through a standardized light-based interface, redesigned using a structured Human Computer Interaction (HCI) design process. The study objectives were to compare different solar home systems and their LED feedback, highlight user understanding challenges resulting from their lack of standardization and compare if a system with standardized LED feedback, designed via a HCI framework, would resolve these challenges. UFuRT (User, Function, Representation and Task analyses) framework was used to evaluate the use of solar-home systems ethnographically and contextually among owners in Rift Valley, Kenya, a high performing sales region for solar home systems. The research adopted both qualitative and quantitative approach in a phased experimental research design. The target population was solar home system owners and a total of 153 owners participated in the study, all selected through convenience sampling. Data collection was done through guide questions administered through in-person interviews which had been content-validated and pilot-validated as a data quality control measure. Data collected was coded and grouped per research objective and then tabulated in a spreadsheet for descriptive analysis. The results obtained from 111 of the solar home system owners indicated that, on average, 51% of solar home system owners could not correctly interpret or did not know the LED feedback of the device they owned. The quantitative and qualitative data collected from the in-person sessions was used to design a simulated standardized interface of a metered solar home system. The effectiveness of this newly designed interface was measured by interviewing another set of 43 solar home system users. The results showed that, on average, up to 63% of solar home system owners correctly interpreted the LED feedback mechanisms of a standardized design. Further, up to 86% of solar home system owners correctly interpreted specific feedback mechanisms of a standardized design. With these findings, the research concludes that using a HCI framework to standardize the interface design of LED-touting devices increases the expressivity and user understanding of feedback relayed by these devices. Thus, manufacturers and industry governing bodies need to consider a universal vocabulary of light-based design that can be widely adopted to solve device usage challenges.