AP Statistics Flashcards: Introduction To Planning A Study

What this deck covers

This deck focuses on Introduction To Planning A Study, giving you a quick way to review the definitions, rules, and examples that matter most for AP Statistics.

How to use these flashcards

Work through these flashcards in short sessions. Try to answer each prompt before flipping the card, then revisit any cards you miss until the explanation feels automatic.

Flashcard 1: Identify the main goal of an observational study.

Answer: The main goal is to describe or compare existing groups without interference. No treatments are imposed; researchers simply observe.

Flashcard 2: What is an observational unit?

Answer: An observational unit is the entity on which measurements are made. The individual item or person being measured.

Flashcard 3: Define a sample in the context of statistical studies.

Answer: A sample is a subset of individuals chosen from a population to represent it. Smaller group used to make inferences about the population.

Flashcard 4: What is the definition of a response variable?

Answer: A response variable is the outcome of interest measured in a study. What researchers want to predict or explain.

Flashcard 5: Define the placebo effect.

Answer: The placebo effect is a beneficial response to a placebo treatment. Shows power of psychological factors in perceived improvement.

Flashcard 6: What does a simple random sample (SRS) mean?

Answer: An SRS is a sample where each set of n individuals has an equal chance of selection. Ensures every possible sample has equal probability of selection.

Flashcard 7: What is the main objective of a census?

Answer: To gather data from every member of the population. Provides complete information but is often impractical.

Flashcard 8: Explain why blinding is used in experiments.

Answer: Blinding prevents bias by ensuring participants or researchers are unaware of group assignments. Reduces expectation effects that could skew results.

Flashcard 9: What is a controlled experiment?

Answer: A controlled experiment involves manipulating one variable to determine its effect. Researchers actively impose treatments to observe effects.

Flashcard 10: Identify one advantage of stratified sampling.

Answer: It increases precision by ensuring representation from each stratum. Reduces variability by controlling for known differences.

Flashcard 11: Differentiate between observational study and experiment.

Answer: In an observational study, variables are not manipulated; in an experiment, they are. Key difference is whether treatments are imposed.

Flashcard 12: Define confounding variable.

Answer: A confounding variable is an outside influence that affects the dependent and independent variables. Can make it impossible to determine true cause-effect relationships.

Flashcard 13: What is the purpose of a pilot study?

Answer: A pilot study tests the feasibility of a larger study. Identifies potential problems before full-scale study.

Flashcard 14: What is a parameter in statistical terms?

Answer: A parameter is a numerical summary of a population. Describes a characteristic of the entire population.

Flashcard 15: Define a sample in the context of statistical studies.

Answer: A sample is a subset of individuals chosen from a population to represent it. Smaller group used to make inferences about the population.

Flashcard 16: What is a parameter in statistical terms?

Answer: A parameter is a numerical summary of a population. Describes a characteristic of the entire population.

Flashcard 17: How does a convenience sample differ from a random sample?

Answer: A convenience sample is chosen based on ease of access, not random selection. Convenience ignores randomness, creating potential bias.

Flashcard 18: Define explanatory variable.

Answer: An explanatory variable is a factor that is manipulated to determine its effect. The variable researchers think causes changes in response.

Flashcard 19: What does a simple random sample (SRS) mean?

Answer: An SRS is a sample where each set of n individuals has an equal chance of selection. Ensures every possible sample has equal probability of selection.

Flashcard 20: What is a controlled experiment?

Answer: A controlled experiment involves manipulating one variable to determine its effect. Researchers actively impose treatments to observe effects.

Flashcard 21: What is the significance of control groups?

Answer: Control groups provide a baseline to compare the effects of treatments. Allow comparison to measure treatment effectiveness.

Flashcard 22: Define a lurking variable.

Answer: A lurking variable is not included as an explanatory or response variable but affects interpretation. Hidden variable that can confound study results.

Flashcard 23: What is a matched pairs design?

Answer: A matched pairs design involves pairing similar units and randomly assigning treatments. Controls for differences between subjects more effectively.

Flashcard 24: What is the role of replication in experiments?

Answer: Replication ensures that results are consistent and not due to chance. Multiple trials help distinguish real effects from random variation.

Flashcard 25: What is the definition of a response variable?

Answer: A response variable is the outcome of interest measured in a study. What researchers want to predict or explain.

Flashcard 26: How is a stratified random sample obtained?

Answer: Divide the population into strata and take an SRS from each stratum. Ensures representation from each important subgroup.

Flashcard 27: Identify the main goal of an observational study.

Answer: The main goal is to describe or compare existing groups without interference. No treatments are imposed; researchers simply observe.

Flashcard 28: What type of study is best for determining causality?

Answer: An experiment is best for determining causality. Only experiments can establish cause-and-effect relationships.

Flashcard 29: What is systematic sampling?

Answer: Systematic sampling involves selecting every k-th individual from a list. Simple method but can introduce bias if pattern exists.

Flashcard 30: What does 'double-blind' mean in an experimental context?

Answer: Neither the participants nor the researchers know who receives the treatment. Prevents expectation bias from both subjects and researchers.

Flashcard 31: Identify the main purpose of random sampling.

Answer: Random sampling ensures each member of the population has an equal chance of selection. Prevents selection bias and enables valid statistical inference.

Flashcard 32: What is a sampling frame?

Answer: A sampling frame is the list or database from which a sample is drawn. The actual list used to select sample members.

Flashcard 33: Define non-response bias.

Answer: Non-response bias occurs when selected participants do not respond. Missing responses may differ systematically from those received.

Flashcard 34: What is an experimental unit?

Answer: An experimental unit is the smallest unit to which a treatment is applied. The individual subject that receives one treatment condition.

Flashcard 35: What is the purpose of randomization in an experiment?

Answer: Randomization helps eliminate bias and balance known and unknown confounding variables. Creates comparable groups by distributing confounding variables evenly.

Flashcard 36: What is the main objective of a census?

Answer: To gather data from every member of the population. Provides complete information but is often impractical.

Flashcard 37: What are the two main types of bias in sampling?

Answer: Selection bias and response bias. Two major sources that can invalidate study results.

Flashcard 38: What is cluster sampling?

Answer: Cluster sampling involves dividing the population into clusters and randomly selecting clusters to sample. Useful when population is naturally grouped geographically.

Flashcard 39: Define the placebo effect.

Answer: The placebo effect is a beneficial response to a placebo treatment. Shows power of psychological factors in perceived improvement.

Flashcard 40: Define confounding variable.

Answer: A confounding variable is an outside influence that affects the dependent and independent variables. Can make it impossible to determine true cause-effect relationships.

Flashcard 41: What does 'response bias' refer to?

Answer: Response bias occurs when participants provide inaccurate answers due to wording or interviewer influence. Question design or interviewer presence affects truthful responses.

Flashcard 42: Define bias in the context of statistical studies.

Answer: Bias is a systematic error that results in an incorrect estimate of an effect. Creates consistently wrong results in a particular direction.

Flashcard 43: Identify one potential issue with convenience sampling.

Answer: It can lead to biased results as it may not represent the entire population. May not represent the target population accurately.

Flashcard 44: What is a sampling frame?

Answer: A sampling frame is the list or database from which a sample is drawn. The actual list used to select sample members.

Flashcard 45: What is the definition of a population in statistics?

Answer: A population is the entire group of individuals or instances about which we seek information. This is the complete group being studied.

Flashcard 46: What is the Hawthorne effect?

Answer: The Hawthorne effect is a change in behavior due to awareness of being observed. Being studied can change natural behavior patterns.

Flashcard 47: Define a lurking variable.

Answer: A lurking variable is not included as an explanatory or response variable but affects interpretation. Hidden variable that can confound study results.

Flashcard 48: Define a statistic in the context of statistical studies.

Answer: A statistic is a numerical summary of a sample. Describes a characteristic calculated from sample data.

Flashcard 49: What is the definition of a population in statistics?

Answer: A population is the entire group of individuals or instances about which we seek information. This is the complete group being studied.

Flashcard 50: What are the two main types of bias in sampling?

Answer: Selection bias and response bias. Two major sources that can invalidate study results.

Flashcard 51: How does a convenience sample differ from a random sample?

Answer: A convenience sample is chosen based on ease of access, not random selection. Convenience ignores randomness, creating potential bias.

Flashcard 52: What is the significance of control groups?

Answer: Control groups provide a baseline to compare the effects of treatments. Allow comparison to measure treatment effectiveness.

Flashcard 53: What is an observational unit?

Answer: An observational unit is the entity on which measurements are made. The individual item or person being measured.

Flashcard 54: Define a statistic in the context of statistical studies.

Answer: A statistic is a numerical summary of a sample. Describes a characteristic calculated from sample data.

Flashcard 55: What is the key characteristic of a voluntary response sample?

Answer: Participants choose themselves to be part of the sample, which can cause bias. Creates strong selection bias toward motivated individuals.

Flashcard 56: What is systematic sampling?

Answer: Systematic sampling involves selecting every k-th individual from a list. Simple method but can introduce bias if pattern exists.

Flashcard 57: What type of study is best for determining causality?

Answer: An experiment is best for determining causality. Only experiments can establish cause-and-effect relationships.

Flashcard 58: What does 'response bias' refer to?

Answer: Response bias occurs when participants provide inaccurate answers due to wording or interviewer influence. Question design or interviewer presence affects truthful responses.

Flashcard 59: Define bias in the context of statistical studies.

Answer: Bias is a systematic error that results in an incorrect estimate of an effect. Creates consistently wrong results in a particular direction.

Flashcard 60: Define explanatory variable.

Answer: An explanatory variable is a factor that is manipulated to determine its effect. The variable researchers think causes changes in response.

Flashcard 61: How does blocking work in experimental design?

Answer: Blocking involves grouping similar experimental units and randomizing within blocks. Reduces variability by controlling for known confounding factors.

Flashcard 62: Identify the purpose of a placebo in experiments.

Answer: A placebo is used to test the efficacy of a treatment by comparing it with a control group. Controls for psychological effects of receiving treatment.

Flashcard 63: What does 'double-blind' mean in an experimental context?

Answer: Neither the participants nor the researchers know who receives the treatment. Prevents expectation bias from both subjects and researchers.

Flashcard 64: Identify the purpose of a placebo in experiments.

Answer: A placebo is used to test the efficacy of a treatment by comparing it with a control group. Controls for psychological effects of receiving treatment.

Flashcard 65: What is the key characteristic of a voluntary response sample?

Answer: Participants choose themselves to be part of the sample, which can cause bias. Creates strong selection bias toward motivated individuals.

Flashcard 66: What is the purpose of randomization in an experiment?

Answer: Randomization helps eliminate bias and balance known and unknown confounding variables. Creates comparable groups by distributing confounding variables evenly.

Flashcard 67: Define non-response bias.

Answer: Non-response bias occurs when selected participants do not respond. Missing responses may differ systematically from those received.

Flashcard 68: What is the role of replication in experiments?

Answer: Replication ensures that results are consistent and not due to chance. Multiple trials help distinguish real effects from random variation.

Flashcard 69: How does blocking work in experimental design?

Answer: Blocking involves grouping similar experimental units and randomizing within blocks. Reduces variability by controlling for known confounding factors.

Flashcard 70: Identify one potential issue with convenience sampling.

Answer: It can lead to biased results as it may not represent the entire population. May not represent the target population accurately.

Flashcard 71: What is an experimental unit?

Answer: An experimental unit is the smallest unit to which a treatment is applied. The individual subject that receives one treatment condition.

Flashcard 72: How is a stratified random sample obtained?

Answer: Divide the population into strata and take an SRS from each stratum. Ensures representation from each important subgroup.

Flashcard 73: Differentiate between observational study and experiment.

Answer: In an observational study, variables are not manipulated; in an experiment, they are. Key difference is whether treatments are imposed.

Flashcard 74: Explain why blinding is used in experiments.

Answer: Blinding prevents bias by ensuring participants or researchers are unaware of group assignments. Reduces expectation effects that could skew results.

Flashcard 75: Identify one advantage of stratified sampling.

Answer: It increases precision by ensuring representation from each stratum. Reduces variability by controlling for known differences.

Flashcard 76: Identify the main purpose of random sampling.

Answer: Random sampling ensures each member of the population has an equal chance of selection. Prevents selection bias and enables valid statistical inference.