What is the theoretical framework used most often in studies of marriage and the family?

It is the social exchange framework.  Social exchange theory is a social mental and sociological point of view that clarifies social change and soundness as a procedure of arranged trades between parties. The hypothesis has established in financial matters, brain science, and human science. 
As indicated by social trade hypothesis, a man who feels that the cost of his or her sentimental relationship exceeds its advantages will undoubtedly leave the relationship.

The best sociological research method would have to be using experiments although it has some disadvantages as well