For a television program about astrology, investigators went into the street and found twenty volunteers born under t...

Naz September 9, 2014

Answer choice (C) states: "The personal impressions the investigators first formed of other people have tended to be confirmed by the investigators' later experience of those people."

This means that the investigators were good judges of the volunteers' personalities, not that they had biases of what the volunteers were going to be like. This answer choice states that the personal impressions that the investigators first formed were CONFIRMED by their subsequent experience with those people, as opposed to the investigator's first impressions influencing how they perceived their subsequent experience with those people.

Thus, the first impressions of the investigators were valid, as opposed to being influenced by biases. The investigators being good judges of character does not describe the flaw in the method used by the investigators.

The issue with their method was that their sample was made up entirely of people who "were willing to be interviewed." That, in itself, creates a self-selecting sample of people who are not afraid to be asked questions for a television program about astrology, i.e. answer choice (E): "People who are not sociable and extroverted are not likely to agree to participate in such an investigation."

Hope that clears things up! Please let us know if you have any other questions.

Abigail-Okereke November 6, 2021

This cleared things up! Just to confirm, this was a biased sampling error?

jakennedy January 19, 2022

Hi @Abigail-Okereke,

That’s exactly right! The sample is biased because they are more likely to be sociable/extroverted in the first place than the population at large for reasons other than their astrological birth sign.