Final answer:
Naomi's approach of gathering feedback from a dinner party is an instance of informal focus group research, which is common in both sociological contexts and business product testing.
Step-by-step explanation:
Naomi's strategy of inviting friends and neighbors over for a dinner to sample her dishes and provide feedback is an example of conducting an informal focus group research. This method is part of the original research designs used in sociological studies and business ventures where feedback is gathered directly from a small, diverse group of people. It's different from options such as secondary research, which involves analyzing existing data; ethnographic studies, which are more about cultural immersion and long-term observation; and branching surveys, which lead participants through different sets of questions based on their previous answers.