Dr. Sears, a psychologist, observes that the more time individuals spend in a department store, the more purchases they tend to make. The research method used in this study is method.

The research method used in this study is Non-experimental method.

Explanation:

The Non-experimental research method occurs when the researcher can not manipulate or control the subjects or independent variable involved in a situation, and therefore have to rely on their observations and interpretation to make a conclusion, such as in the example given: Dr. Sears draws a conclusion of a situation and participants he can not manipulate (the individuals in a department store) based on observations made.

fertile good for trade etc