Andee Kaplan

Designing Modular Software: A Case Study in Introductory Statistics

ABSTRACT Modular programming is a development paradigm that emphasizes self-contained, flexible, and independent pieces of functionality. This practice allows new features to be seamlessly added when desired, and unwanted features to be removed, thus simplifying the softwares user interface. The recent rise of web-based software applications has presented new challenges for designing an extensible, modular software system. In this article, we outline a framework for designing such a system, with a focus on reproducibility of the results. We present as a case study a Shiny-based web application called intRo, that allows the user to perform basic data analyses and statistical routines. Finally, we highlight some challenges we encountered, and how to address them, when combining modular programming concepts with reactive programming as used by Shiny. Supplementary material for this article is available online.

Visualizing communication patterns at DinoFun World

Two IDs are notable for their large volume of messages: 1278894 and 839736. These IDs are responsible for almost 80% of the message volume. Both these ids are stationary, sending messages from the Entry Corridor only. From the pattern of messages sent and received we are able to identify these ids as the parks help line (839736) and the Cindysaurus trivia game (1278894), which is part of the DinoFun World app (IEEE VAST Challenge 2015).

On the move at DinoFun world

Overall attendance at DinoFun World is characterized in figure 2. The number of moves park-goers make is charted for each minute of the day along a horizontal time axis. We can learn a couple of things from this plot: (1) the Scott Jones show was held from 10 to 11 during all mornings and from 3 to 4 in the afternoons of Friday and Saturday. We can see this from the dip in movements (orange lines are average number of moves during one hour) during this time, and the spikes immediately at the end of the show (when a lot of people move out of the area). The second show on Sunday was cancelled: the dip in movements is missing on Sunday afternoon. This is also visible in figure 2, showing check-ins by area: people check into the Grinosaurus Stage, where the Scott Jones show is hosted, before 10 am for all days but before 3 pm only on Friday and Saturday. (2) there is a spike in movements on Sunday at around 2:30 pm - judging from the movement pattern these are people on their way to the Scott Jones show who get turned away (because there are no check-ins to the Grinosaurus Stage), see also figure 3.