AP stats unit 4 flashcards

What is a population in a statistical study?

The entire group of individuals about which we want information.

What is a sample in statistics?

The part of the population from which we actually collect information.

What indicates bias in a statistical study?

The design of a study shows bias if it systematically favors certain outcomes.

What is a convenience sample?

A sample chosen that is readily available, often leading to biased results.

Why are voluntary response samples biased?

Because individuals with strong opinions are more likely to respond.

What is undercoverage bias?

When some groups in the population are left out of the sample selection process.

What is non-response bias?

When individuals chosen for the sample cannot be contacted or refuse to participate.

What is response bias?

When individuals do not answer questions truthfully, leading to systematic errors.

What is wording bias?

When the phrasing of a question influences the responses given by participants.

What is a simple random sample?

A sample obtained by randomly selecting individuals from a target population.

What is a stratified random sample?

A sample created by dividing the population into strata based on shared characteristics.

What is cluster sampling?

A sampling method where the population is divided into clusters, and entire clusters are randomly selected.

What is sampling error?

Errors that come from the act of choosing a sample.

What defines a sample survey?

It selects a sample from the population to gather information.

What is a systematic random sample?

A sample selected at regular intervals from a randomly ordered list of the population.

What is a multistage sample?

A sample that breaks down the population into two or more situations.

What is an observational study?

A study that observes individuals and measures variables without influencing responses.

What is an experimental study?

A study that imposes treatments on individuals to measure their responses.

What is a lurking variable?

A variable not included in a study that may influence the response variable.

What is a confounding variable?

Variable effects are intertwined where their effects on a response variable cannot be distinguished.

What is treatment in an experiment?

A specific condition applied to individuals in an experiment.

What are subjects in an experiment?

The smallest collection of individuals to whom treatments are applied.

What is a placebo?

A dummy pill or inactive treatment indistinguishable from the real treatment.

What is random assignment?

The chance process used to assign experimental units to treatments.

What is a comparative experiment?

An experiment where some units receive one treatment and similar units receive another.

What is a control group?

The group that receives an inactive or baseline treatment.

What is replication in experimental design?

Using enough experimental units so differences can be distinguished from chance differences.

What is a randomized block design?

Random assignment of experimental units done separately within blocks based on variability.

What is a matched-pairs design?

A design comparing two treatments where each subject receives both treatments, often in random order.

What does statistically significant mean?

An observed effect unlikely to occur by chance, indicating possible causation.

What is an explanatory variable?

The variable being manipulated in an experiment.

What is a response variable?

The concept or quantity that is being measured in an experiment.

What are the challenges of establishing causation?

Criteria including the strength, consistency, and plausibility of the association.

What does inference in experiments entail?

Well-designed experiments randomly assigning individuals to treatment groups.

What are the basic ethics of data collection?

Studies must be reviewed for safety, subjects must give consent, and data must remain confidential.