New App Shows Online Discussions as Interactive Graphs

Nebula encourages students to discuss work outside of class

Nebula displays conversations as interactive graphs, in which posts are the nodes and replies are the links.Nebula displays conversations as interactive graphs, in which posts are the nodes and replies are the links.

This past spring, Seyed Iravani’s service operations management course was running smoothly with the exception of one hiccup. He and his teaching assistant Jackie Ng struggled to motivate their students to participate in online conversations, supplementing course material between classes. Even after the pair offered extra credit for contributing to the discussion board, only half the class participated — and begrudgingly so.

“We were not happy with the low participation rate,” said Iravani, professor of industrial engineering and management sciences at Northwestern Engineering. “We wanted to discover how to encourage our students to participate more.”

Having done research in complex systems, Iravani and Ng decided to visualize discussion boards as social network graphs, where the nodes are people and links are the replies to posts. The pair then approached Bill Parod and Jacob Collins in Northwestern Information Technology. After many conversations, they together came up with Nebula, a visual graphical interface to the traditional discussion board. The new tool presents discussions as a network graph, in which posts are the nodes and replies are the links among nodes.

For online discussions, most classes use a traditional discussion board within Canvas, Northwestern’s cloud-based learning management system. Nebula is an application that can be installed directly into Canvas, making it compatible with any Canvas course.

Traditional discussion boards typically display posts in a chronological list. The discussions can be difficult to navigate, making it tricky to decide which posts to read and reply to. Users have a tendency to only view and respond to recent posts, while older posts are more likely to be overlooked and abandoned.

Seyed Iravani“Sometimes, by the time you get down to the fifth comment, you forget what the original question was,” Iravani said. “In Nebula, you can see the history of an entire discussion branching from the question that was posted.”

Although the networks are a simple way to convey discussions at a glance, the nodes communicate complex information. They are color-coded to help users distinguish between read and unread messages and are bigger relative to the length of the post. They are also marked with the contributor’s initials, so participants can see who is talking and who is not. This can spur game-like competitions that motivate participation. But, more importantly, it helps students feel more prepared and excited about class.

“Students sometimes don’t feel comfortable talking in class, especially in front of their peers on a topic that they might not know much about,” said Ng, a PhD student in Iravani’s lab. “Using Nebula, they can think aloud by writing their thoughts, validate them with their classmates, and learn from what others are saying. It helps them formulate and refine their thoughts. Then we have higher-level discussions in class.”

Iravani and Ng also contend that Nebula promotes the collaborative, team-based culture that greatly benefits student learning and achievement. At the McCormick School of Engineering, engineers have grown accustomed to working in teams and sharing ideas with each other. With Nebula, instructors can provide an opportunity for students to meet in their small groups online between classes to contemplate course material and learn from one another. 

So far, Iravani and Professors Noshir Contractor and Bill White are using Nebula with good results, and several others have expressed interest in adding it to their classes. All have witnessed online discussions increase in frequency and quality. Because Nebula works on mobile devices, students can comment whenever and wherever they feel inspired.

“Students now contribute to discussions regularly,” Ng said. “They are learning from each other and thinking about the material more outside of class. Nebula takes learning outside the classroom and makes it a part of daily life.”

A specially designed instructor app accompanies Nebula, enabling instructors to track and score student activity. It also allows instructors to message students privately or post publically to a group.

“Considering the trend toward online education, this is a positive step in improving our teaching,” Iravani said. “It’s all for better learning. Whatever can help our students learn better is a win for us.”