Statistical Bias - B10

What is a population?

• A tool used to collect statistical data

• Statistics collected from an entire population

• All the people or objects on which data is collected

• A group chosen from a population

What is statistics?

• The science of collecting and analysing data

• Statistics collected from an entire population

• An element or feature that can vary

• A group chosen from a population

An error that comes from selecting a sample that does not represent the population

• confounding variable

• sample bias

• nonresponse bias

• placebo

A school randomly chose ten English teachers and asked them which type of juice their students would prefer. Which reason best shows why this sample is biased?

• The sample didn't include students.
• The sample is too small.
• The sample can only be accurate if each teacher is included in the sample

Why do we randomly select our samples?

• for control
• reduce bias
• so we don't get the same answers from everyone
• to eliminate confounding results

Source of bias that occurs when you ask people who are EASY to ask

• Response Bias
• Convenience Sampling
• Nonresponse
• Voluntary Response

Source of bias in which people CHOOSE to respond and usually only people with very strong opinions respond

• Response Bias
• Undercoverage
• Convenience Sampling
• Voluntary Response

Source of bias in which some groups of populations are LEFT OUT of the selection process

• Response Bias
• Undercoverage
• Convenience Sampling
• Voluntary Response

Source of bias that occurs when an individual chosen for the sample CAN'T be contacted or refuses to cooperate.

• Response Bias
• Undercoverage
• Nonresponse
• Voluntary Response

I want to estimate the proportion of all adults in Chula Vista who graduated from high school. I select a random sample of addresses and go to those houses. When an adult answers the door, I ask if they had graduated from high school. If a child answers the door, I ask for an adult. If there is none there at the time, I return at another time to complete the survey. What is the most prominent bias?

• Non-response bias

• Response bias

• Voluntary response bias

• Undercoverage