A comparison of field-based and lab-based experiments to evaluate user experience of personalised mobile devices

There is a growing debate in the literature regarding the tradeoffs between lab and field evaluation of mobile devices. This paper presents a comparison of field-based and lab-based experiments to evaluate user experience of personalised mobile devices at large sports events. A lab experiment is recommended when the testing focus is on the user interface and application-oriented usability related issues. However, the results suggest that a field experiment is more suitable for investigating a wider range of factors affecting the overall acceptability of the designed mobile service. Such factors include the system function and effects of actual usage contexts aspects. Where open and relaxed communication is important (e.g., where participant groups are naturally reticent to communicate), this is more readily promoted by the use of a field study

NPRF: A Neural Pseudo Relevance Feedback Framework for Ad-hoc Information Retrieval

Pseudo-relevance feedback (PRF) is commonly used to boost the performance of traditional information retrieval (IR) models by using top-ranked documents to identify and weight new query terms, thereby reducing the effect of query-document vocabulary mismatches. While neural retrieval models have recently demonstrated strong results for ad-hoc retrieval, combining them with PRF is not straightforward due to incompatibilities between existing PRF approaches and neural architectures. To bridge this gap, we propose an end-to-end neural PRF framework that can be used with existing neural IR models by embedding different neural models as building blocks. Extensive experiments on two standard test collections confirm the effectiveness of the proposed NPRF framework in improving the performance of two state-of-the-art neural IR models.Comment: Full paper in EMNLP 201

Mobile personalization in the context of large sports events

The paper reports a study of mobile personalization in the context of large sport events, specifically with Chinese users. The study compared the user experience obtained by Chinese spectators at a large sports event when using a prototype mobile application that either did, or did not, allow personalization. The study found that mobile personalization could play an important role in enriching the user experience at large sport events, but also had some potential drawbacks. In addition, limitations were identified with existing user centred design methods with Chinese users and suggestions for appropriate evaluation methods for these users are made

Mobile personalization at large sports events : user experience and mobile device personalization

Mobile personalization is frequently discussed, and has been shown in relation to a number of usage scenarios. However, this research has focused mainly on technology development. There have been few studies of mobile user experience, and personalization in sports. This paper is devoted to the new field of studying the user experience related to mobile personalization at large sports events (LSE). In order to support and enrich the user experience at LSE with mobile personalization, this study investigates the current audience experience at stadiums and derives the usage patterns that device personalization could usefully support in this context

The role of spatial contextual factors in mobile personalization at large sports events

This paper presents three field studies undertaken at large sports events in the UK and China, with aim of improving the user experience at these types of events through the design of personally-relevant mobile services. These field studies investigated: which aspects of spatial context were relevant within the confines of a large sporting event, how their relevance differed according to sports event and language/culture, and how they could be used to prescribe the behaviour of a personalizable/adaptive mobile device. Spatial aspects of context were found to be highly significant within the large sports arena. They can be used to maximize the relevance of information and communication services delivered to a spectator over a mobile device. A range of design implications are discussed

Design of the user experience for personalized mobile services

This article describes how user centered, and particularly co-design methods can help maximize user experience for personalized services delivered over a mobile device. The specific focus was designing for Chinese spectators at large sports events (such as football matches, swimming galas or athletics meetings). User experience was assumed to comprise user, product, social, cultural and usage context components. Co-design methods were incorporated into a semi- structured HCI design process that comprised content, conceptual, interaction and presentation design, followed by field and lab-based user evaluation. There were two co-design methods in particular which were found to be key to working effectively with Chinese users. Emotion Cards were used to help overcome some of the inhibitions of participants and to encourage them to provide more open and unequivocal design input. The User Advisory Board was a group of participants who mediated the relationship between the designer and other participants at various design stages. They helped to ensure genuine collaboration because the wider participants felt (1) less like the object of study and (2) more able to communicate their needs during the design process

The impact of user- and system-initiated personalization on the user experience at large sports events

This article describes an experimental study investigating the impact on user experience of two approaches of personalization of content provided on a mobile device, for spectators at large sports events. A lab-based experiment showed that a system-driven approach to personalization was generally preferable, but that there were advantages to retaining some user control over the process. Usability implications for a hybrid approach, and design implications are discussed, with general support for countermeasures designed to overcome recognised limitations of adaptive systems

Comprehensive Demonstration of Spin-Hall Hanle Effects in Epitaxial Pt Thin Films

We demonstrate a nonlinear Hall effect due to the boundary spin accumulation in Pt films grown on Al2O3 substrates. This Hall effect and the previously demonstrated Hanle magnetoresistance provide a complete picture of the spin-precession control of the spin and charge transport at the boundary of a spin-orbit coupled material, which we refer to as spin-Hall Hanle effects (SHHE). We also show that the SHHE can be employed to measure the spin diffusion length, the spin-Hall angle, and the spin relaxation time of heavy metal without the need of magnetic interface or the input from other measurements. The comprehensive demonstration of SHHE in such a simple system suggests they may be ubiquitous and needs to be considered for unravelling the spin and charge transport in more complex thin film structures of spin-orbit coupled materials

Giant interfacial spin-Hall angle from Rashba-Edelstein effect revealed by the spin-Hall Hanle processes

The Rashba-Edelstein effect (REE), which generates interfacial spin polarization and subsequent spin current, is a compelling spin-charge conversion mechanism for spintronics applications, since it is not limited by the elemental spin-orbit coupling. In this work, we demonstrate REE at Pt/ferroelectric interfaces using the recently elucidated spin-Hall Hanle effects (SHHE), in which a Larmor precession of spin polarization in a diffusion process from the interface manifest as magnetoresistance and Hall effect. We show that REE leads to a three-fold enhancement of the effective spin Hall angle in ferroelectric interface Pt/h-LuFeO3 compared to that of Pt /Al2O3, although the difference in the spin relaxation time is negligible. Modeling using SHHEs involving REE as an additional source of interfacial polarization suggests that REE can lead to an interfacial spin Hall angle (~0.3) that is one order of magnitude larger than the bulk value of Pt. Our results demonstrate that a ferroelectric interface can produce large spin-charge conversion and that SHHEs are a sensitive tool for characterizing interfacial spin transport properties