AP Statistics Flashcards: Random Sampling And Data Collection

What this deck covers

This deck focuses on Random Sampling And Data Collection, 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: What is the difference between qualitative and quantitative data?

Answer: Qualitative data is descriptive; quantitative data is numerical. Different analysis methods apply to each type.

Flashcard 2: What is a simple random sample?

Answer: A sample where each member has an equal chance of selection. Ensures randomness and prevents selection bias.

Flashcard 3: What does 'randomization' achieve in an experiment?

Answer: It controls for confounding variables and reduces bias. Essential principle for valid experimental design.

Flashcard 4: What is voluntary response bias?

Answer: Bias that occurs when individuals can choose to participate. Creates unrepresentative samples with extreme views.

Flashcard 5: What is a double-blind experiment?

Answer: Neither the subjects nor the researchers know who receives the treatment. Eliminates bias from expectations and placebo effects.

Flashcard 6: Explain the term 'population' in statistics.

Answer: The entire group of individuals or instances about whom we hope to learn. Target group for statistical inference and conclusions.

Flashcard 7: Identify the effect of leading questions on data collection.

Answer: They can introduce response bias by influencing participants' answers. Compromises data validity and reliability.

Flashcard 8: Identify the effect of leading questions on data collection.

Answer: They can introduce response bias by influencing participants' answers. Compromises data validity and reliability.

Flashcard 9: Define proportional sampling.

Answer: Sampling method where the proportion of each subgroup in the sample matches the population. Maintains population structure in sample composition.

Flashcard 10: What is the significance of sample size in data collection?

Answer: Larger samples reduce sampling error and increase result reliability. Follows law of large numbers for accuracy.

Flashcard 11: What is random assignment?

Answer: Randomly assigning subjects to treatment groups to control for confounding variables. Minimizes confounding and ensures fair comparison.

Flashcard 12: What is non-response bias?

Answer: Bias introduced when responses are not obtained from all selected participants. Creates incomplete data and potential bias.

Flashcard 13: Define confounding variable.

Answer: An external variable that affects both the independent and dependent variables. Must be controlled to establish valid causal relationships.

Flashcard 14: What is the main goal of data collection?

Answer: To gather accurate and reliable data relevant to the research question. Enables evidence-based decision making and inference.

Flashcard 15: What is a convenience sample?

Answer: Sample selected based on ease of access. Not random; prone to selection bias.

Flashcard 16: What is random assignment?

Answer: Randomly assigning subjects to treatment groups to control for confounding variables. Minimizes confounding and ensures fair comparison.

Flashcard 17: What is the role of an independent variable in an experiment?

Answer: The variable manipulated to observe its effect on the dependent variable. The factor being tested for its effect.

Flashcard 18: Identify what an outlier is in data collection.

Answer: An observation that lies an abnormal distance from other values. May indicate data errors or unusual observations.

Flashcard 19: Define observational study.

Answer: Researcher observes subjects without manipulation. Cannot establish causation, only association.

Flashcard 20: Explain response bias.

Answer: Bias that occurs when participants provide inaccurate responses. Results from measurement errors or participant dishonesty.

Flashcard 21: Define sampling distribution.

Answer: The probability distribution of a given statistic based on a random sample. Foundation for statistical inference about populations.

Flashcard 22: What is an experiment in statistics?

Answer: Study where the researcher manipulates one or more variables to observe effects. Allows researchers to establish causal relationships.

Flashcard 23: What is a placebo?

Answer: An inactive substance given to the control group in an experiment. Controls for psychological effects of treatment.

Flashcard 24: What is non-response bias?

Answer: Bias introduced when responses are not obtained from all selected participants. Creates incomplete data and potential bias.

Flashcard 25: Define multistage sampling.

Answer: Sampling method that involves multiple stages of sampling, often combining methods. Complex but efficient for large, dispersed populations.

Flashcard 26: Define sampling distribution.

Answer: The probability distribution of a given statistic based on a random sample. Foundation for statistical inference about populations.

Flashcard 27: Identify the purpose of a control group.

Answer: To serve as a baseline for comparison with the treatment group. Enables comparison to measure treatment effects.

Flashcard 28: Identify the purpose of clustering in sampling.

Answer: To divide the population into clusters and randomly select entire clusters. Efficient when population naturally groups together.

Flashcard 29: Define proportional sampling.

Answer: Sampling method where the proportion of each subgroup in the sample matches the population. Maintains population structure in sample composition.

Flashcard 30: What is quota sampling?

Answer: Sampling method where quotas are set for different subgroups of the population. Non-random method that can introduce bias.

Flashcard 31: Identify the meaning of 'replication' in experiments.

Answer: Repeating an experiment to confirm results. Increases confidence in experimental results.

Flashcard 32: What is meant by 'sampling error'?

Answer: The difference between a sample statistic and the corresponding population parameter. Natural variation inherent in sampling process.

Flashcard 33: What is the significance of sample size in data collection?

Answer: Larger samples reduce sampling error and increase result reliability. Follows law of large numbers for accuracy.

Flashcard 34: Define random sampling error.

Answer: The error due to chance variation in selecting a random sample. Unavoidable variability in random sampling process.

Flashcard 35: What is a census in the context of data collection?

Answer: The collection of data from every member of the population. Expensive and time-consuming; rarely practical.

Flashcard 36: What is a sampling frame?

Answer: A list of all individuals or units in the population from which the sample is drawn. Should ideally include all population members.

Flashcard 37: What is a simple random sample?

Answer: A sample where each member has an equal chance of selection. Ensures randomness and prevents selection bias.

Flashcard 38: What is the role of an independent variable in an experiment?

Answer: The variable manipulated to observe its effect on the dependent variable. The factor being tested for its effect.

Flashcard 39: Identify what an outlier is in data collection.

Answer: An observation that lies an abnormal distance from other values. May indicate data errors or unusual observations.

Flashcard 40: Identify the role of pilot studies in sampling.

Answer: Conducted to test the feasibility and improve the design of the study. Identifies problems before full-scale data collection.

Flashcard 41: Define a dependent variable.

Answer: The variable being measured or tested in an experiment. The outcome variable showing treatment effects.

Flashcard 42: What is meant by 'sampling error'?

Answer: The difference between a sample statistic and the corresponding population parameter. Natural variation inherent in sampling process.

Flashcard 43: What is a systematic sample?

Answer: Select every $k^{th}$ member from a list of the population. Provides systematic coverage with random starting point.

Flashcard 44: What is meant by 'blinding' in experiments?

Answer: Concealing information from participants to reduce bias. Prevents bias from participant and researcher expectations.

Flashcard 45: Define undercoverage bias.

Answer: Occurs when some members of the population are inadequately represented in the sample. Results from incomplete sampling frame coverage.

Flashcard 46: What is an experiment in statistics?

Answer: Study where the researcher manipulates one or more variables to observe effects. Allows researchers to establish causal relationships.

Flashcard 47: Define undercoverage bias.

Answer: Occurs when some members of the population are inadequately represented in the sample. Results from incomplete sampling frame coverage.

Flashcard 48: What is a convenience sample?

Answer: Sample selected based on ease of access. Not random; prone to selection bias.

Flashcard 49: Explain response bias.

Answer: Bias that occurs when participants provide inaccurate responses. Results from measurement errors or participant dishonesty.

Flashcard 50: Identify the purpose of a control group.

Answer: To serve as a baseline for comparison with the treatment group. Enables comparison to measure treatment effects.

Flashcard 51: What is quota sampling?

Answer: Sampling method where quotas are set for different subgroups of the population. Non-random method that can introduce bias.

Flashcard 52: What is the main goal of data collection?

Answer: To gather accurate and reliable data relevant to the research question. Enables evidence-based decision making and inference.

Flashcard 53: What is the difference between a parameter and a statistic?

Answer: Parameter describes a population; statistic describes a sample. Parameters are fixed values; statistics are calculated estimates.

Flashcard 54: Identify the meaning of 'replication' in experiments.

Answer: Repeating an experiment to confirm results. Increases confidence in experimental results.

Flashcard 55: Define bias in the context of sampling.

Answer: Systematic error that results in a non-representative sample. Creates unrepresentative samples and invalid conclusions.

Flashcard 56: What is a placebo?

Answer: An inactive substance given to the control group in an experiment. Controls for psychological effects of treatment.

Flashcard 57: Define bias in the context of sampling.

Answer: Systematic error that results in a non-representative sample. Creates unrepresentative samples and invalid conclusions.

Flashcard 58: Define a dependent variable.

Answer: The variable being measured or tested in an experiment. The outcome variable showing treatment effects.

Flashcard 59: Identify the purpose of clustering in sampling.

Answer: To divide the population into clusters and randomly select entire clusters. Efficient when population naturally groups together.

Flashcard 60: What is the benefit of random sampling?

Answer: Reduces bias and ensures each member of the population has an equal chance of selection. Creates representative samples for valid inference.

Flashcard 61: What is a census in the context of data collection?

Answer: The collection of data from every member of the population. Expensive and time-consuming; rarely practical.

Flashcard 62: Define a stratified random sample.

Answer: Population divided into strata; random samples taken from each stratum. Ensures representation from each subgroup.

Flashcard 63: What does 'randomization' achieve in an experiment?

Answer: It controls for confounding variables and reduces bias. Essential principle for valid experimental design.

Flashcard 64: What is the difference between a parameter and a statistic?

Answer: Parameter describes a population; statistic describes a sample. Parameters are fixed values; statistics are calculated estimates.

Flashcard 65: What is a systematic sample?

Answer: Select every $k^{th}$ member from a list of the population. Provides systematic coverage with random starting point.

Flashcard 66: What is a double-blind experiment?

Answer: Neither the subjects nor the researchers know who receives the treatment. Eliminates bias from expectations and placebo effects.

Flashcard 67: Define multistage sampling.

Answer: Sampling method that involves multiple stages of sampling, often combining methods. Complex but efficient for large, dispersed populations.

Flashcard 68: Define random sampling error.

Answer: The error due to chance variation in selecting a random sample. Unavoidable variability in random sampling process.

Flashcard 69: What is the difference between qualitative and quantitative data?

Answer: Qualitative data is descriptive; quantitative data is numerical. Different analysis methods apply to each type.

Flashcard 70: What is the benefit of random sampling?

Answer: Reduces bias and ensures each member of the population has an equal chance of selection. Creates representative samples for valid inference.

Flashcard 71: What is the Hawthorne effect?

Answer: Subjects change behavior because they know they are being observed. Threatens validity of observational studies.

Flashcard 72: What is meant by 'blinding' in experiments?

Answer: Concealing information from participants to reduce bias. Prevents bias from participant and researcher expectations.

Flashcard 73: Define a stratified random sample.

Answer: Population divided into strata; random samples taken from each stratum. Ensures representation from each subgroup.

Flashcard 74: Identify the role of pilot studies in sampling.

Answer: Conducted to test the feasibility and improve the design of the study. Identifies problems before full-scale data collection.

Flashcard 75: Explain the term 'population' in statistics.

Answer: The entire group of individuals or instances about whom we hope to learn. Target group for statistical inference and conclusions.

Flashcard 76: Define observational study.

Answer: Researcher observes subjects without manipulation. Cannot establish causation, only association.