Described the theoretical framework as a rainbow arc, bridging the dependent and independent variables to provide an overarching explanation of how and why the independent variable may predict [or affect] the dependent variable. It will help to review Creswell's definitions of dependent and independent variables [Chap.3, p. 50], which were also pointed out in the M1.A2 Discussion about setting up your potential research questions using the relational model.
To further explain Creswell's rainbow arc metaphor with an example: If the independent variable in a relational research question is types of classroom educational practices and the dependent variable is student success in learning, envision how a theory like Gardner's theory of multiple intelligences could be the theoretical framework or rainbow arc a researcher might use as a possible explanatory link for how one variable predicts the other. In this case, the theoretical perspective is that multiple intelligence theory applied to classroom educational practices could impact student success in learning. Since there are many possible theories that could connect these two variables, can you see how focusing on a single theory might focus this research question?
Another example from your recent article critique: Consider how Langer (2002) used theories about the concept of reflection, under his heading, "The Concept of Reflection in Learning," as a theoretical/conceptual framework, or lens, as a way to frame the concept of journals as a learning tool for adults (p. 338), citing definitions of reflection from different researchers. He could have taken quite a different approach with different theories, for example, adult learning theories, for his ‘rainbow arc' to connect the variables that framed the research question for his study.