Evaluation of Daylight Perception Assessment Methods

Daylight is an important component in maintaining human health and wellbeing and plays a key role in physiological, psychological, and behavioural regulation. Understanding the complexity of daylight perception is vital since the degree of satisfaction with daylight conditions could greatly impact individual mood, behaviour and cognitive performance. This paper aims at (1) presenting an overview of current knowledge on methods for assessing daylight perception and (2) establishing a methodology for assessing daylight perception in the context of cultural background. An experiment was conducted with 50 students who were instructed to select the best and worst seats, describe the best desks’ daylight conditions and draw boundary lines between perceived daylit and non-daylit spaces in a library. The study showed that subjective rating and seat preference methods were consistent with actual daylight levels. However, participants’ boundary lines did not represent the actual daylight availability in the space. The study suggests that individual daylight perception in the context of cultural background can be assessed using the subjective rating and seat preference methods

The growing and risky industry of nomadic apps for drivers

HCI researchers have worked for decades defining methods and techniques to assess the attention demands of in-vehicle information systems (IVIS). Acceptance test methods have been proposed that must be passed for the safe use of IVIS. Most of these methods require expensive test environments and highly trained personnel for its implementation. This article makes a review of those strategies with focus in the cost and development process phase. In the realm of mobile application ecosystems (aka apps ), guidelines and certification programs exist. Apps must pass them to be considered as automotiveready systems or to integrate with OEM infotainment devices. However, getting into the category of certified applications does not guarantee full compliance with the criteria established by formal methods accepted by the automotive industry and international standards. Moreover, many studies show the high risk of using IVIS while driving, which lead to consider that the current predominant approaches to assess attention demands of automotive apps and to guide IVIS design are not enough. Efficient cost-benefit methods applicable in early phases of application development, as well as context-adaptive interfaces have the potential to contribute to the improvement of safe driving environments

The growing and risky industry of nomadic apps for drivers

HCI researchers have worked for decades defining methods and techniques to assess the attention demands of in-vehicle information systems (IVIS). Acceptance test methods have been proposed that must be passed for the safe use of IVIS. Most of these methods require expensive test environments and highly trained personnel for its implementation. This article makes a review of those strategies with focus in the cost and development process phase. In the realm of mobile application ecosystems (aka "apps"), guidelines and certification programs exist. Apps must pass them to be considered as automotive-ready systems or to integrate with OEM infotainment devices. However, getting into the category of certified applications does not guarantee full compliance with the criteria established by formal methods accepted by the automotive industry and international standards. Moreover, many studies show the high risk of using IVIS while driving, which lead to consider that the current predominant approaches to assess attention demands of automotive apps and to guide IVIS design are not enough. Efficient cost-benefit methods applicable in early phases of application development, as well as context-adaptive interfaces have the potential to contribute to the improvement of safe driving environments.Laboratorio de Investigación y Formación en Informática Avanzad

ROLE OF CONTEXT IN USABILITY EVALUATIONS: A REVIEW

ABSTRACT Usability is often defined as the ability of a system to carry out specific tasks by specific users in a specific context. Usability evaluation involves testing the system for its expected usability. Usability testing is performed in natural environment (field) or artificial environment (laboratory). The result of usability evaluation is affected by the environment in which it is carried out. Previous studies have focused only on the physical environment (lab and field) effect on the results but rarely focused on the effect of social environment (people present during testing). Therefore, this study aims to review how important it is to take context into account during usability evaluation. Context is explored through the theory of behaviour settings, according to which behaviour of individuals is strongly influenced by the physical as well as the social environment in which they function. The result of this review indicates tha

"Accessibility Map" and "Social navigator" services for persons with disabilities

The paper describes development process of information environment for persons with disabilities. Introduction describes the aim and objectives of development, the results of evaluation of typical demands and user scenarios for persons with disabilities. The first section of the main part describes common applications architecture and utilized technologies. Both services use the same data model, which includes description of route parts and roads, as well as information about accessibility of objects stored in the database of “Accessibility Passports” service developed previously. The next section contains description of the development process. The user scenarios, service functions, the use of Geo2Tag platform and Open Street Map with its libraries are presented. In “Social navigator” service the routes are described as a graph with weighted edges, where the weight is the rate of accessibility of the path parts. The mathematical method for estimation of accessibility according to various types of ability restrictions was developed and implemented in the service. The method is based on graph theory and provides an approach to formal ranging of the routes according to the accessibility level of persons with limited mobility

Contrast measures for predicting perceptual effects of daylight in architectural renderings

Daylit architecture is perceived as a dynamic luminous composition, yet most existing performance metrics were designed to evaluate natural illumination for its ability to adequately illuminate a two-dimensional task surface and avoid glare-based discomfort. It may be argued that task-driven approaches based on surface illumination and glare ignore the likelihood that contrast can provide positive impacts on our visual perception of space. Advances in these metrics to accommodate climate-based sky conditions and occupant behavior have improved our ability to evaluate task illumination and glare, yet the same attention has not been paid to evaluating positive perceptual responses to daylight. Existing studies have attempted to link subjective ratings of composition to simple global contrast metrics without reaching consensus. More advanced metrics have been developed in computational graphics and vision fields, but have not been applied to studies in qualitative lighting research. This paper introduces the results from an online experiment where subject ratings of daylight composition are compared to quantitative contrast measures across a series of renderings. This paper will identify which measures correlate to subjects’ ratings of visual interest, and introduces a modified contrast algorithm, which can be used as a novel prediction model for visual interest in daylit renderings

Optimizing Content Caching and Recommendations with Context Information in Multi-Access Edge Computing

Recently, the coupling between content caching at the wireless network edge and video recommendation systems has shown promising results to optimize the cache hit and improve the user experience. However, the quality of the UE wireless link and the resource capabilities of the UE are aspects that impact user experience and that have been neglected in the literature. In this work, we present a resource-aware optimization model for the joint task of caching and recommending videos to mobile users that maximizes the cache hit ratio and the user QoE (concerning content preferences and video representations) under the constraints of UE capabilities and the availability of network resources by the time of the recommendation. We evaluate our proposed model using a video catalog derived from a real-world video content dataset and real-world video representations and compare the performance with a state-of-the-art caching and recommendation method unaware of computing and network resources. Results show that our approach increases user QoE by at least 68% and effective cache hit ratio by at least 14% in comparison with the other method