Question

All of the following are examples of an observational study EXCEPT:

a. scanning and recording bar codes of products purchased
b. a consumer responding to a questionnaire about advertising
c. a cable laid across the street that records the number of cars that pass a certain intersection
d. a mystery shopper pretending to be a customer in a McDonald’s outlet
e. An employee pretending to be a customer at a cosmetics counter in a department store

Answer 1

The only option that is not an example of an observational study is 'a consumer responding to a questionnaire about advertising', as this represents survey research involving a questionnaire, whereas the other options are true observational studies where researchers observe natural occurrences without interventions.

Step-by-step explanation:

The student's question is asking which of the provided options is not an example of an observational study. An observational study is a research method where the researcher measures characteristics but does not manipulate the variables. The only option that involves an intervention is 'a consumer responding to a questionnaire about advertising' because it involves a survey aspect where the researcher's measurements consist of questionnaires that are responded to by research participants. Conversely, scanning and recording barcodes, counting cars with a cable, and employees pretending to be customers are all instances where researchers observe without intervening, thus representing true observational studies.