Conference papers by Derek C Weber
Interfaces for Discourse Summarisation: A Human Factors Analysis
OzCHI 2013, Nov 2013
Empirical studies assessing the effectiveness of novel document interfaces are becoming more prev... more Empirical studies assessing the effectiveness of novel document interfaces are becoming more prevalent, however relatively little attention has been paid to how such tools could work with less structured documents featuring multiple contributors. Participants in this study used different interfaces to answer questions requiring the exploration of collaborative discourse. User performance was influenced by an interaction of interface, transcript, and question type. Individual differences also impacted on performance with higher education levels and higher general knowledge scores being associated with better task performance. The results also revealed that unnecessary interface functionality can hinder performance.
Proceedings of Concept Lattices and Their Applications 2018, 2018
Formal Concept Analysis takes as input a bigraph known as a formal context. It produces a partial... more Formal Concept Analysis takes as input a bigraph known as a formal context. It produces a partially-ordered set of formal concepts which constitutes a complete lattice. This lattice can be represented as a directed acyclic graph, whose vertices are formal concepts and whose arcs connect neighbours in the ordering relation between them. This paper describes a divide-and-conquer technique for discovering and exploiting hierarchical structure in a formal context. Simultaneous hierarchical partitioning of both the context bigraph and the resultant lattice digraph is used to achieve efficient computation and, elsewhere, interactive visualisation of the concept lattice.
Enhancing Layout and Interaction in Formal Concept Analysis
Proceedings of the 2014 IEEE Pacific Visualisation Symposium (PacificVis), 2014
Formal Concept Analysis (FCA) derives a multiple-inheritance class hierarchy from a formal contex... more Formal Concept Analysis (FCA) derives a multiple-inheritance class hierarchy from a formal context. The number of classes is bounded above by an exponential function of the number of objects and attributes in the context. To support interactive analysis of large formal contexts, this paper exploits a divide-and-conquer technique which discovers hierarchical structure in amenable formal contexts. That hierarchical structure is used to expedite and enhance both the layout of, and user interaction with, the concept lattice. The principal contribution is the dual use of the discovered hierarchical structure for scalable, interactive FCA.
Papers by Derek C Weber
Social Network Analysis and Mining
During Australia’s unprecedented bushfires in 2019–2020, misinformation blaming arson surfaced on... more During Australia’s unprecedented bushfires in 2019–2020, misinformation blaming arson surfaced on Twitter using . The extent to which bots and trolls were responsible for disseminating and amplifying this misinformation has received media scrutiny and academic research. Here, we study Twitter communities spreading this misinformation during the newsworthy event, and investigate the role of online communities using a natural experiment approach—before and after reporting of bots promoting the hashtag was broadcast by the mainstream media. Few bots were found, but the most bot-like accounts were social bots, which present as genuine humans, and trolling behaviour was evident. Further, we distilled meaningful quantitative differences between two polarised communities in the Twitter discussion, resulting in the following insights. First, Supporters of the arson narrative promoted misinformation by engaging others directly with replies and mentions using hashtags and links to external so...
Formal Concept Analysis takes as input a bigraph known as a formal context. It produces a partial... more Formal Concept Analysis takes as input a bigraph known as a formal context. It produces a partially-ordered set of formal concepts which constitutes a complete lattice. This lattice can be represented as a directed acyclic graph, whose vertices are formal concepts and whose arcs connect neighbours in the ordering relation between them. This paper describes a divide-and-conquer technique for discovering and exploiting hierarchical structure in a formal context. Simultaneous hierarchical partitioning of both the context bigraph and the resultant lattice digraph is used to achieve efficient computation and, elsewhere, interactive visualisation of the concept lattice.
During the summer of 2019-20, while Australia suffered unprecedented bushfires across the country... more During the summer of 2019-20, while Australia suffered unprecedented bushfires across the country, false narratives regarding arson and limited backburning spread quickly on Twitter, particularly using the hashtag #ArsonEmergency. Misinformation and bot- and troll-like behaviour were detected and reported by social media researchers and the news soon reached mainstream media. This paper examines the communication and behaviour of two polarised online communities before and after news of the misinformation became public knowledge. Specifically, the Supporter community actively engaged with others to spread the hashtag, using a variety of news sources pushing the arson narrative, while the Opposer community engaged less, retweeted more, and focused its use of URLs to link to mainstream sources, debunking the narratives and exposing the anomalous behaviour. This influenced the content of the broader discussion. Bot analysis revealed the active accounts were predominantly human, but beh...
Formal Concept Analysis takes as input a bigraph known as a formal context. It produces a partial... more Formal Concept Analysis takes as input a bigraph known as a formal context. It produces a partially-ordered set of formal concepts which constitutes a complete lattice. This lattice can be represented as a directed acyclic graph, whose vertices are formal concepts and whose arcs connect neighbours in the ordering relation between them. This paper describes a divide-and-conquer technique for discovering and exploiting hierarchical structure in a formal context. Simultaneous hierarchical partitioning of both the context bigraph and the resultant lattice digraph is used to achieve efficient computation and, elsewhere, interactive visualisation of the concept lattice.
: This report explores the effect of interruption from instant messaging (IM) on memory of a vide... more : This report explores the effect of interruption from instant messaging (IM) on memory of a video-teleconference brief. A 4x2 factorial pilot study was conducted with 32 participants (gender balanced), using four levels of interruption and gender as the independent variables. Two videos were presented to participants, one of a single person speaking and one of a pair in conversation. Memory was tested with five minutes free recall after each video and recognition questionnaires 24 hours later. Analysis revealed that women performed better than men in free recall, that requiring participants to respond to questions degraded their free recall, and that interruption caused a significant downward trend in free recall performance and confidence. Recognition performance results were inconclusive, however. We recommend repeating this study with more participants. Results obtained could help advise Defence on the development of usage policies for collaboration technologies, specifically re...
Social Network Analysis and Mining
To study the effects of online social network (OSN) activity on real-world offline events, resear... more To study the effects of online social network (OSN) activity on real-world offline events, researchers need access to OSN data, the reliability of which has particular implications for social network analysis. This relates not only to the completeness of any collected dataset, but also to constructing meaningful social and information networks from them. In this multidisciplinary study, we consider the question of constructing traditional social networks from OSN data and then present several measurement case studies showing how variations in collected OSN data affect social network analyses. To this end, we developed a systematic comparison methodology, which we applied to five pairs of parallel datasets collected from Twitter in four case studies. We found considerable differences in several of the datasets collected with different tools and that these variations significantly alter the results of subsequent analyses. Our results lead to a set of guidelines for researchers planning to collect online data streams to infer social networks.
Social Network Analysis and Mining
Political misinformation, astroturfing and organised trolling are online malicious behaviours wit... more Political misinformation, astroturfing and organised trolling are online malicious behaviours with significant real-world effects that rely on making the voices of the few sounds like the roar of the many. These are especially dangerous when they influence democratic systems and government policy. Many previous approaches examining these phenomena have focused on identifying campaigns rather than the small groups responsible for instigating or sustaining them. To reveal latent (i.e. hidden) networks of cooperating accounts, we propose a novel temporal window approach that can rely on account interactions and metadata alone. It detects groups of accounts engaging in various behaviours that, in concert, come to execute different goal-based amplification strategies, a number of which we describe, alongside other inauthentic strategies from the literature. The approach relies upon a pipeline that extracts relevant elements from social media posts common to the major platforms, infers connections between accounts based on criteria matching the coordination strategies to build an undirected weighted network of accounts, which is then mined for communities exhibiting high levels of evidence of coordination using a novel community extraction method. We address the temporal aspect of the data by using a windowing mechanism, which may be suitable for near real-time application. We further highlight consistent coordination with a sliding frame across multiple windows and application of a decay factor. Our approach is compared with other recent similar processing approaches and community detection methods and is validated against two politically relevant Twitter datasets with ground truth data, using content, temporal, and network analyses, as well as with the design, training and application of three one-class classifiers built using the ground truth; its utility is furthermore demonstrated in two case studies of contentious online discussions.
#ArsonEmergency and Australia’s “Black Summer”: Polarisation and Misinformation on Social Media
Disinformation in Open Online Media
2014 IEEE Pacific Visualization Symposium, 2014
Formal Concept Analysis (FCA) derives a multiple-inheritance class hierarchy from a formal contex... more Formal Concept Analysis (FCA) derives a multiple-inheritance class hierarchy from a formal context. The number of classes is bounded above by an exponential function of the number of objects and attributes in the context. To support interactive analysis of large formal contexts, this paper exploits a divide-and-conquer technique which discovers hierarchical structure in amenable formal contexts. That hierarchical structure is used to expedite and enhance both the layout of, and user interaction with, the concept lattice. The principal contribution is the dual use of the discovered hierarchical structure for scalable, interactive FCA.
Effects of Instant Messaging on Recall During Video-Mediated Briefings
An architecture for multi-view information overlays
Proceedings of the 2004 Australasian Symposium on Information Visualisation Volume 35, 2004
This paper describes an architecture for supporting multi-view information overlays within the In... more This paper describes an architecture for supporting multi-view information overlays within the InVision visualisation framework. The concept of an information overlay is defined as well its key benefits, including the ability to support coordination of presentation across differing ...
Proceedings 1998 Australasian Computer Human Interaction Conference. OzCHI'98 (Cat. No.98EX234), 1998
Microsoft Windows 95 uses both vertical arrangements of items in lists as well as horizontal grou... more Microsoft Windows 95 uses both vertical arrangements of items in lists as well as horizontal groupings of smaller vertical lists. This paper reports the results of an experiment to evaluate selection times using horizontal and vertical lists. Two GOMS models were developed to predict differences. There was no significant difference in times, but results showed interesting trends in learning behaviour.
Interfaces for discourse summarisation: A human factors analysis
ABSTRACT Empirical studies assessing the effectiveness of novel document interfaces are becoming ... more ABSTRACT Empirical studies assessing the effectiveness of novel document interfaces are becoming more prevalent, however relatively little attention has been paid to how such tools could work with less structured documents featuring multiple contributors. Participants in this study used different interfaces to answer questions requiring the exploration of collaborative discourse. User performance was influenced by an interaction of interface, transcript, and question type. Individual differences also impacted on performance with higher education levels and higher general knowledge scores being associated with better task performance. The results also revealed that unnecessary interface functionality can hinder performance.
Chapters by Derek C Weber
Scalable Visual Analytics in FCA
Formal Concept Analysis as Explainable Support for Complex Data Analytics, 2021
Formal Concept Analysis (FCA) is suitable for use within organisations at different levels of mat... more Formal Concept Analysis (FCA) is suitable for use within organisations at different levels of maturity in information management and big data analytics. It takes as input a bigraph, into which both structured and unstructured data can be readily transformed, and produces a multiple-inheritance type hierarchy suitable for formal knowledge representation. Accordingly, FCA has been widely applied in areas such as information retrieval, knowledge discovery and knowledge representation. The multiple-inheritance hierarchy produced by FCA is a complete lattice which can be represented as a labelled, directed, acyclic graph. We adopt a visual analytic approach to FCA by combining computational analysis with interactive visualisation. Scaling FCA to the interactive analysis of large data sets poses three fundamental challenges: the time required to enumerate the vertices, arcs and labels of the lattice digraph; the difficulty of responsive presentation of, and meaningful user interaction with, a large digraph; and the discovery of insightful implications. This chapter briefly surveys potential solutions to these scalability challenges posed by big data volumes, and describes software prototypes and coordinated visualisations which explore some of them.
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Conference papers by Derek C Weber
Papers by Derek C Weber
Chapters by Derek C Weber