An important step in a dissertation is the theoretical basis that might help explain and shed light on why the problem is happening. For example, if we want to know a certain population does not want to use Cell Phones, we may decide to use an Adoption model, like the Technology Adoption Model to gather data to see if the variables in TAM could help explain why this population you have chosen does not want to use Cell Phones.

Discuss the model, theory, framework you think helps explains why this problem is happening. Remember, this reason will also be cited in the literature as well, so make sure to include scholarly resources.