Introduction to the new usability

This paper introduces the motivation for and concept of the "new usability" and positions it against existing approaches to usability. It is argued that the contexts of emerging products and systems mean that traditional approaches to usability engineering and evaluation are likely to prove inappropriate to the needs of "digital consumers." The paper briefly reviews the contributions to this special issue in terms of their relation to the idea of the "new usability" and their individual approaches to dealing with contemporary usability issues. This helps provide a background to the "new usability" research agenda, and the paper ends by posing what are argued to be the central challenges facing the area and those which lie at the heart of the proposed research agenda

Statistical Studies of Giant Pulse Emission from the Crab Pulsar

We have observed the Crab pulsar with the Deep Space Network (DSN) Goldstone 70 m antenna at 1664 MHz during three observing epochs for a total of 4 hours. Our data analysis has detected more than 2500 giant pulses, with flux densities ranging from 0.1 kJy to 150 kJy and pulse widths from 125 ns (limited by our bandwidth) to as long as 100 microseconds, with median power amplitudes and widths of 1 kJy and 2 microseconds respectively. The most energetic pulses in our sample have energy fluxes of approximately 100 kJy-microsecond. We have used this large sample to investigate a number of giant-pulse emission properties in the Crab pulsar, including correlations among pulse flux density, width, energy flux, phase and time of arrival. We present a consistent accounting of the probability distributions and threshold cuts in order to reduce pulse-width biases. The excellent sensitivity obtained has allowed us to probe further into the population of giant pulses. We find that a significant portion, no less than 50%, of the overall pulsed energy flux at our observing frequency is emitted in the form of giant pulses.Comment: 19 pages, 17 figures; to be published in Astrophysical Journa

Zero-shot Clustering of Embeddings with Self-Supervised Learnt Encoders

We explore whether self-supervised pretrained models can provide a useful representation space for datasets they were not trained on, and whether these representations can be used to group novel unlabelled data into meaningful clusters. To this end, we conduct experiments using image representation encoders pretrained on ImageNet using a variety of self-supervised training techniques. These encoders are deployed on image datasets that were not seen during training, without fine-tuning, and we investigate whether their embeddings can be clustered with conventional clustering algorithms. We find that it is possible to create well-defined clusters using self-supervised feature encoders, especially when using the Agglomerative Clustering method, and that it is possible to do so even for very fine-grained datasets such as NABirds. We also find indications that the Silhouette score is a good proxy of cluster quality when no ground-truth is available

Postgraduate Spotlights:Using a Community of Inquiry approach to enhance student engagement in geographical higher education

While the majority of pedagogical practice has been affected by the COVID-19 pandemic, the teaching of geographical research skills has been especially difficult with the loss of fieldwork and practical applications. Furthermore, the move to online teaching has diminished the learning communities in face-to-face classrooms. In an attempt to counteract these issues, this paper reflects on a learning activity in an undergraduate geographical research methods course, ‘Postgraduate Spotlights’ where two postgraduate researchers presented their specialist research methods followed by an interactive question-and-answer session with the undergraduates. We (as postgraduates, undergraduates and teaching staff) found that the open and critical discussion in the workshop fostered a Community of Inquiry that encouraged engagement from students stimulating their curiosity about geographical research methods. Through our discussion, we demonstrate the importance of having postgraduate researchers involved in teaching, as Graduate Teaching Assistants (GTAs) given their liminal role of researcher-learner. We also emphasise the importance of letting the students lead their own learning, building a Community of Inquiry across academic stages, and creating a constructive dialogue around geographical research methods. While the reproducibility of the workshop face-to-face remains to be seen, this article emphasises the potential for applying such an approach to stimulate free-flowing discussion and ultimately promote a Community of Inquiry