Introduction:
Sociological theories provide a framework for understanding and analyzing various social phenomena, including changing family structures and roles. By applying sociological theories to the study of family dynamics, researchers can gain deeper insights into the factors influencing these changes and their consequences for individuals and society as a whole.

Functionalism:
- According to functionalism, families serve specific functions in society, such as socializing children, providing emotional support, and maintaining social order.
- Analyzing changing family structures through the functionalist lens would involve examining how these changes impact the ability of families to fulfill their functions.
- For example, as more women enter the workforce, the traditional gender roles within families may shift, affecting the division of labor and the socialization of children.

Conflict Theory:
- Conflict theorists emphasize the power dynamics and inequality within society.
- Analyzing changing family structures from a conflict theory perspective would involve exploring how power struggles and inequalities shape these changes.
- For instance, the increase in single-parent households can be attributed to economic inequalities and the unequal distribution of resources.

Symbolic Interactionism:
- Symbolic interactionism focuses on the meanings and symbols that individuals attach to their social interactions.
- Analyzing changing family structures through symbolic interactionism would involve examining how individuals' interpretations and interactions contribute to shaping family roles and structures.
- For instance, the redefinition of marriage and the acceptance of same-sex marriages reflect changing societal attitudes and the negotiation of new meanings and symbols attached to family relationships.

Feminist Theory:
- Feminist theory explores gender inequalities and the social construction of gender roles.
- Analyzing changing family structures from a feminist theory perspective would involve examining how gender norms and power dynamics influence these changes.
- For example, the increasing prevalence of dual-income households may challenge traditional gender roles, but it can also reinforce gender inequalities if women continue to bear the majority of household and childcare responsibilities.

Conclusion:
By utilizing sociological theories, researchers can gain a comprehensive understanding of changing family structures and roles. Functionalism helps analyze the functions families serve, conflict theory examines power dynamics and inequalities, symbolic interactionism focuses on individual interactions and meanings, and feminist theory explores gender inequalities. By applying these theories, researchers can better understand the causes and consequences of changing family structures and roles in society.