For Some Reason, You Are Fascinated with Dog Parks, and Want

For some reason, you are fascinated with dog parks, and want to conduct a systematic observational study of the dynamics of people's behavior while at the dog park. What are the important factors to consider when designing your study? For example, given that you want the study to be very naturalistic, you would want to ensure that the behaviors being exhibited are an existing part of people's repertoire, that the setting is not perceived by park goers to be artificially constructed for the purposes of research, and that any "treatments" are such that park goers would have experienced these discrete events with or without the presence of a researcher. Besides the degree of "naturalness," what are three of the factors that one must consider when designing a naturalistic observational study? In your response, be sure to (a) describe each of the three factors; (b) explain the different considerations for each factor, and the benefits and drawbacks to these considerations; and (c) provide an example for how each factor would manifest in the context of observation of the dog park (i.e., what would your decision regarding each factor look like had you actually conducted the observational study?).
Answer template:
Factors or dimensions to consider:
a. observer involvement in the natural setting
b. how extensive or intensive will the coding scheme be
c. will they use qualitative, quantitative, or both types of coding
d. how will they classify the unit of observation.