Sampling Bias and Representativeness

Miss Norris explains the concept of samples and populations in research, emphasizing the importance of representative samples. She provides four examples to illustrate good and bad sampling methods. The first example shows a biased sample of kindergarteners for school lunch preferences. The second example demonstrates a good sample for predicting a school election winner. The third example uses systematic sampling to assess YouTube watching habits. The fourth example highlights bias in sampling for movie preferences. The video concludes with a summary of the importance of representative samples.

What is the term used to describe the entire group you are interested in studying?

• Sample

• Group

• Subject

• Population

What is a 'subject' in the context of samples and populations?

• A small group

• A large group

• A type of sample

• One person or thing

Which of the following is a characteristic of a good sample?

• It is very small

• It is biased

• It is representative

• It focuses on one type of subject

Which of the following is NOT a reason a sample might be considered bad?

• It is biased

• It is too small

• It is representative

• It focuses on one type of subject

Why is the sample in the school lunch preference survey considered biased?

• It only surveys kindergarteners

• It is randomly selected

• It includes too many students

• It surveys students from all grades

In the school lunch preference survey, what is the main reason the sample does not represent all students?

• It includes all grades

• It only includes kindergarteners

• It is randomly selected

• It is too large

In the school election prediction example, why is the sample considered representative?

• It only includes seniors

• It focuses on one type of student

• It is too small

• It is randomly selected

What is the benefit of randomly selecting students in a sample?

• It focuses on one type of student

• It makes the sample too small

• It ensures bias

• It increases representativeness

What method is used in the YouTube watching habits study to ensure a representative sample?

• Asking every student

• Asking only teachers

• Asking only friends

• Asking every tenth student

In the YouTube watching habits study, what is the advantage of asking every tenth student?

• It makes the sample too small

• It ensures bias

• It focuses on one type of student

• It increases representativeness