Answer:
A problem known as a sampling error.
Step-by-step explanation:
Sampling error refers to the error that occurs when the researcher does not select a correct sample, that is, he does not select a sample that is efficient in representing a group or a population. In this case, the conclusions that the experiment presents are inaccurate and cannot be considered credible. An example of this can be seen in the above question, where, seeking to represent journalists from all over the country, the researcher selected only journalists from Chicago to compose a sample. Chicago journalists are not enough to represent an entire country, so we can say that this experiment contains a sampling error.