ChaRLeS: An Open-Source Chat Room Learning System Edoardo Bontà, Giovanni Torrisi, Marco Bernardo Università di Urbino edoardo.bonta@uniurb.it

Who’s ChaRLeS? ChaRLeS is a virtual classroom that recreates an environment of a physical university classroom multi-channel layered textual chat LTI provider for Moodle and other learning management systems real-time web application open-source software

Why ChaRLeS? ChaRLeS is an acronym for Chat Room Learning System. We developed it to overcome the weaknesses of other textual chat rooms (as the Moodle one) by taking care of: functionality: multi-channel text chat features and filtered history log (see later) efficiency: recent technologies, like HTML5 WebSockets, have been employed for sending/receiving messages with very low latency and reduced bandwidth consumption usability: simple, intuitive, mobile-first, responsive, and user-friendly interfaces. No single-lined text area, no forced scroll every 3 seconds, no fragmented chat sessions / history logs portability: any device (PC, smartphone, tablet) with an updated browser enabling JavaScript is enough at the client side. Major operating systems, i.e. Windows / Linux / MacOSX, can host the application at the server side … but also reliability and maintainability, of course!

The underlying chat model The underlying model of ChaRLeS addresses some common text chat room inefficiencies (Vronay, 1999) including: Lack of intention indicators (difficulty to understand who a message is addressed to) Low signal-to-noise ratio (didactic info mixed up with socialization or service messages) Uselessness of chat history (lack of thread coherence, fragmentation, interruptions) … and other functional issues 4-channel layered interaction system: Lecture channel: used by the instructor, it can also be enabled for students [recorded] Question channel: used by students, questions are submitted by the instructor [recorded] Service channel: used by all for greetings and organizational messages Private channel: used by all for sending private messages to selected users A similar model has been successfully applied to the chat room of Land of Learning (LoL), an old proprietary LMS using Java applets for asynchronous messaging [Mec Informatica (www.mecinformatica.it), Roma, & University of Urbino (www.uniurb.it)]

Architecture of the web application ChaRLeS Hosting support (server) Self-hosting: ASP.NET Core for Windows, Linux, MacOSX Client application Service Real-time web application written in pure HTML + JavaScript Other useful JS libs JQuery, Bootstrap Real-time JS library SignalR.js Real-time support SignalR Web service support web API Custom services written in C# Reverse Proxy (Nginx) HTTP Application path http://localhost:[port]/charles/... HTTP + WebSocket Service paths http://localhost:[port]/charles/signalr/... http://localhost:[port]/charles/api/... Unified path https://mydomain.com/charles/... https://mydomain.com/charles/signalr/... https://mydomain.com/charles/api/... https://mydomain.com/<other apps/services> HTTPS + WebSocket relative references Other apps/services

The chat room instance page of ChaRLeS

… and the points of view of Steve and Leo

The chat room session log The history log of the chat room session is as follows: Programming Languages - A.A. 2015/2016 - 10 CFU Last session start time: 01/09/2016 09:15:00 [server local time] <Question from Steve Smith> What does OOP mean? <John Doe> It stands for "Object-Oriented Programming" Two terms that I often hear are "business logic" and "presentation logic" Business logic is the domain logic, that's the part of a program encoding the real-world business rules.

Configuration of the Moodle plugin mod_charles

Conclusion and future work The outcome of the chat model and of the design/implementation of the architecture is ChaRLeS, an easy-to-use textual chat room, that can be interfaced with Moodle or other LMSs through the LTI protocol. Common textual chat inefficiencies have been addressed thanks to the multi-channel layered interaction model. Performance and other technical issues have been addressed by developing the web application with the help of new technologies, as HTML5 WebSockets and real-time libraries (SignalR). Future work LaTeX equation editor based on JS library MathJax; Virtual whiteboard relying on SVG (Scalable Vectorial Graphics) image format; Instant poll for receiving immediate feedbacks from participants.