This course focuses on social norms. These are the rules that bind societies together. This course teaches you how to identify social norms and distinguish them from other social constructs like conventions or customs. This distinction is crucial to effective policy interventions that create or remove new and beneficial norms. This course will teach you how to assess social norms, the expectations they support and determine whether certain behaviors are caused by them. This joint Penn-UNICEF course includes examples of norms supporting behaviors such as child marriage, gender violence, and sanitation practices. This Part 1 is part of the Social Norms, Social Change Series. These lectures introduce the fundamental concepts and definitions of social expectations, conditional preferences and how they can be used to distinguish among different social practices such as customs, social norms, and descriptive norms. These lectures will show you how to measure expectations and preferences. It is essential to measure the practices you face in order to understand their nature and determine whether or not an intervention has been successful. We will apply all the lessons learned in Part 1 to Part 2.