content area top Part 1 It is extremely important for a researcher to clearly define the variables in a study because this helps to determine the type of analysis that can be performed on the data. For example, if a researcher wanted to describe countries based on ISBN left parenthesis International Standard Book Number right parenthesis group identifier, what level of measurement would the variable "ISBN group identifier" be? Now suppose the researcher felt that certain countries with a larger total area received higher identifying numbers. Does the level of measurement of the variable change? If so, how