This concluding commentary takes the perspective of research on practicing scientists and engineers to consider what open areas and future directions on relational thinking and learning should be considered beyond the impressive research presented in the special issue. Areas for more work include (a) a need to examine educational applications of relational thinking in divergent reasoning, rather than primarily in convergent reasoning; (b) considerations of when to "not" focus on relational reasoning in learning; (c) more research on the distributed nature of relational reasoning across students in a class, and to embedded physical, social, and historical contexts; (d) treatment of the hot components of relational reasoning including motivational and emotional processes; and (e) more attention to how relational reasoning is changed by the details of modalities rather than treating all contents as abstract symbols.