After S9 proposed the initial node on March 15, 2020, students continued to add to the node as they learned more material from "The Book of Why." Immediately after creating the node, S9 linked this to the node "Randomized Controlled Trial (RCT" created by S6, a concept that was referenced in this node. This interaction shows how students can link and relate the knowledge they learn to others' contributions.

S10 later proposed an improvement on S9's node on April 2, to add "front-door criterion" to the list on the node. This contribution shows that students could build on previous contributions that other students have made and improve them as they learn more about the subject.

S11 improved this node on April 12 to change the title to "Eliminating Non-Measurable Confounder Variables" stating in their proposal reasoning that "This update reflects the conversation from the 4/5 discussion. We update the title to discuss eliminating non-measurable confounders, and simplify the strategies into two: RCT and observational studies." S11 helps to specify that these methods specified for deconfounding are used for non measurable variables and further clarifies the distinction between "RCT" and "back-door criterion" and "front-door criterion" by noting how "front-door criterion," "back-door criterion," as well as "do-calculus" are methods that can be used with "RCT" and "observational studies" rather than being directly comparable. This contribution shows how students were able to help correct misconceptions and help clarify details about concepts to help each other learn more effectively.