Jointly constructed explanation

Jointly constructed explanation: a statement or set of statements, spread across two (or more) speakers that makes explicit the causal or relational connection between concepts. Here is an example of a jointly constructed explanation in the domain of kinematics (from Hausmann, Chi, & Roy, 2004):

Jill:	Force acting on block B, is different from force acting on block A.
Sara:	Ok. Because their mass, is different.
Jill:	Yeah. Because-yeah.

Jill presents a proposition (i.e., the forces are different), and Sara supplies the justification (i.e., because the masses are different).