Reusing Interactive Analysis Workflows

Interactive visual analysis has many advantages, but has the disadvantage that analysis processes and workflows cannot be easily stored and reused, which is in contrast to scripted analysis workflows using a programming language such as Python. In this paper, we introduce methods to semantically capture workflows in interactive visualization systems for different interactions such as selections, filters, categorizing/grouping, labeling, and aggregation. We design these workflows to be robust to updates in the dataset by capturing the semantics of underlying interactions, and, hence, they can be applied to updated datasets. We demonstrate this specification using a prototype that visualizes the data, shows interaction provenance, and allows generating workflows from this provenance. Finally, we introduce a Python library that can consume the workflow and apply it to the datasets, providing a seamless bridge between computational workflows and interactive visualization tools. We demonstrate our techniques using our UI prototype and Jupyter notebooks.

Interactive Visual Analysis of Translations

This thesis is the result of a collaboration with the College of Arts and Humanities at Swansea University. The goal of this collaboration is to design novel visualization techniques to enable digital humanities scholars to explore and analyze parallel translations. To this end, chapter 2 introduces the first survey of surveys on text visualization which reviews all of the surveys and state-of-the-art reports on text visualization techniques, classifies them, provides recommendations, and discusses reported challenges.Following this, we present three visual interactive designs that support the typical digital humanities scholars workflow. In Chapter 4, we present VNLP, a visual, interactive design that enables users to explicitly observe the NLP pipeline processes and update the parameters at each processing stage. Chapter 5 presents AlignVis, a visual tool that provides a semi-automatic alignment framework to build a correspondence between multiple translations. It presents the results of using text similarity measurements and enables the user to create, verify, and edit alignments using a novel visual interface. Chapter 6 introduce TransVis, a novel visual design that supports comparison of multiple parallel translations. It incorporates customized mechanisms for rapid and interactive filtering and selection of a large number of German translations of Shakespeare’s Othello. All of the visual designs are evaluated using examples, detailed observations, case studies, and/or domain expert feedback from a specialist in modern and contemporary German literature and culture.Chapter 7 reports our collaborative experience and proposes a methodological workflow to guide such interdisciplinary research projects. This chapter also includes a summary of outcomes and lessons learned from our collaboration with the domain expert. Finally, Chapter 8 presents a summary of the thesis and future work directions.

Interactive Visual Analysis of Mass Spectrometry Imaging Data Using Linear and Non-Linear Embeddings

Mass spectrometry imaging (MSI) is an imaging technique used in analytical chemistry to study the molecular distribution of various compounds at a micro-scale level. For each pixel, MSI stores a mass spectrum obtained by measuring signal intensities of thousands of mass-to-charge ratios (m/z-ratios), each linked to an individual molecular ion species. Traditional analysis tools focus on few individual m/z-ratios, which neglects most of the data. Recently, clustering methods of the spectral information have emerged, but faithful detection of all relevant image regions is not always possible. We propose an interactive visual analysis approach that considers all available information in coordinated views of image and spectral space visualizations, where the spectral space is treated as a multi-dimensional space. We use non-linear embeddings of the spectral information to interactively define clusters and respective image regions. Of particular interest is, then, which of the molecular ion species cause the formation of the clusters. We propose to use linear embeddings of the clustered data, as they allow for relating the projected views to the given dimensions. We document the effectiveness of our approach in analyzing matrix-assisted laser desorption/ionization (MALDI-2) imaging data with ground truth obtained from histological images.