Enhancing the Interactive Visualisation of a Data Preparation Tool from in-Memory Fitting to Big Data Sets.

In order to derive reliable insights or make evidence-based decisions, the starting point is to assess and meet a minimum quality of data, either by those that publish the data (preferably) or alternatively by those that prepare data for analysis and develop specific analytics. Much of the (open) data shared by governments and different institutions, or crowdsourced, is in tabular format, and the amount and size of it is increasing rapidly. This paper presents the challenges faced and the solutions adopted while evolving the web-based graphical user interface (GUI) of a tabular data preparation tool from in-memory fitting to Big Data sets. Traditional standalone processing and rendering solutions are no longer usable in a Big Data context. We report on the approach adopted to asynchronously precompute the visualisations required for the tool, in addition to the applied visualisation aggregation strategies. The implementation of this approach has allowed us to overcome web-browsers' client-side data handling limitations and to avoid information overloadwhen using granular information charts from our existing in-memory data preparation tool with Big Data sets. The developed solution provides the user with an acceptable GUI interaction time.