What are the variables to be included and excluded?In research?

Variables that need to be included or excluded are defined by the research being done and its limitations also.

OR Inclusion and exclusion criteria may include factors such as age, sex, race, ethnicity, type and stage of disease, the subject's previous treatment history, and the presence or absence (as in the case of the “healthy” or “control” subject) of other medical, psychosocial, or emotional conditions.

well stockyards mean a large yard containing pens and sheds, typically adjacent to a slaughterhouse, in which livestock is kept and sorted. and i'm assuming that by party you   mean a large group of people which does make sense because chicago is a very crowded place much like new york. stockyards tend to take up a lot of room due to needing the area for pens to keep animals in and the fact that stockyards are usually right by slaughterhouse where they process and distribute the product. so its much like a zoo but with some dead animal products close by.

one thousand and one nights, also known as arabian nights is a collection of stories whose basic structure is that of embedded narrative. this technique refers to a main story which works as the common frame - or framing narrative - for the other stories, and then this series of stories which are connected to the main one. this technique can also be referred to as a story within a story. the stories stem from the original tale, some begin and end on their own, some are connected to the previous or following one, by means of questions that are answered in the subsequent tale, or characters which reappear.