Trace alignment is the problem of finding the best possible execution sequence of a business process (BP) model that reproduces an (observed) execution trace of the same BP by pinpointing where it deviates. One limiting assumption that governs the state-of-the-art alignment algorithms relies in a static cost function assigning fixed costs to all the possible types of deviations related to a BP activity, thus neglecting the specific context in which the deviation takes place and flattening the analysis of its potential impact. In this paper, we relax this assumption by providing a technique based on theoretic manipulations of deterministic finite state automata (DFAs) to build optimal alignments driven by dedicated cost models that assign context-dependent variable costs to the deviations. We show how the algorithm can be implemented relying on automated planning in Artificial Intelligence (AI), which is proven to be an effective tool to address the alignment task in the case of BP models and event logs of remarkable size. Finally, we report on the results of experiments conducted in a real-life case study on incident management and on larger synthetic ones performed through three well-known planning systems to showcase the performance, scalability and versatility of our technique.

Progressive visual analytics allows users to interact with early, partial results of long-running computations on large datasets. In this context, computational steering is often brought up as a means to prioritize the progressive computation. This is meant to focus computational resources on data subspaces of interest so as to ensure their computation is completed before all others. Yet, current approaches to select a region of the view space and then to prioritize its corresponding data subspace either require a one-to-one mapping between view and data space, or they need to establish and maintain computationally costly index structures to trace complex mappings between view and data space. We present steering-by-example, a novel interactive steering approach for progressive visual analytics, which allows prioritizing data subspaces for the progression by generating a relaxed query from a set of selected data items. Our approach works independently of the particular visualization technique and without additional index structures. First benchmark results show that steering-by-example considerably improves Precision and Recall for prioritizing unprocessed data for a selected view region, clearly outperforming random uniform sampling.

In this paper, we present a new benchmark to validate the suitability of database systems for interactive visualization workloads. While there exist proposals for evaluating database systems on interactive data exploration workloads, none rely on real user traces for database benchmarking. To this end, our long term goal is to collect user traces that represent workloads with different exploration characteristics. In this paper, we present an initial benchmark that focuses on "crossfilter"-style applications, which are a popular interaction type for data exploration and a particularly demanding scenario for testing database system performance. We make our benchmark materials, including input datasets, interaction sequences, corresponding SQL queries, and analysis code, freely available as a community resource, to foster further research in this area: https://osf.io/9xerb/?view_only=81de1a3f99d04529b6b173a3bd5b4d23.

We present the innovative visual analytics approach of the VATE system, which eases and makes more effective the experimental evaluation process by introducing the what-if analysis. The what-if analysis is aimed at estimating the possible effects of a modification to an IR system to select the most promising fixes before implementing them, thus saving a considerable amount of effort. VATE builds on an analytical framework which models the behavior of the systems in order to make estimations, and integrates this analytical framework into a visual part which, via proper interaction and animations, receives input and provides feedback to the user.