Statistics Terms to Know

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Questions and Answers

What is a variable in the context of a study?

A method for choosing individuals for a sample

A characteristic of an individual (correct)

An explanation for a response

A numerical summary of a population

A parameter is a summary of values for a sample.

False

What is the difference between a retrospective study and a prospective study?

A retrospective study looks back at past events, while a prospective study follows subjects into the future.

A __________ sample is chosen using a probability method.

probability Signup and view all the answers

Match the sampling methods with their descriptions:

Simple random sample = Each individual has an equal chance of selection Stratified random sample = Dividing the population into strata and sampling from each Cluster random sample = Selecting whole clusters and pooling individuals from them Convenience sample = Drawing from those who are easily available Signup and view all the answers

What is a confounding variable?

A variable that influences the relationship between studied variables Signup and view all the answers

Response bias occurs when individuals provide incorrect answers due to poorly worded questions.

True Signup and view all the answers

Define sampling bias.

Sampling bias occurs when there is a systematic tendency to exclude one type of individual from a study. Signup and view all the answers

Match the following terms with their definitions:

Statistic = A numerical summary of values based on a sample Parameter = A numerical summary of values for the entire population Variable = A characteristic of an individual Sample = A subset of the study populations made of individuals Signup and view all the answers

Match the following types of studies with their characteristics:

Prospective Study = Follows subjects into the future Retrospective Study = Looks backward in time to past events Comparative Study = Establishes cause and effect relationships Observational Study = Values of variables are observed without testing Signup and view all the answers

Match the following sampling methods with their descriptions:

Probability Sample = Chosen using a probability method Convenience Sample = Not chosen using a probability method Simple Random Sample = Each possible sample has the same chance of selection Stratified Random Sample = Divides population into groups and samples from each Signup and view all the answers

Match the following biases with their descriptions:

Sampling Bias = Systematic tendency to exclude certain individuals Nonresponse Bias = Occurs when a person chooses not to respond Response Bias = Occurs when a person responds incorrectly Measurement Bias = Inaccuracy in the process of measuring outcomes Signup and view all the answers

Match the following variables with their explanations:

Response Variable = Measures an outcome or result of interest Explanatory Variable = Helps explain changes in a response variable Lurking Variable = Influences relationships among variables but is not measured Confounding Variable = Effects on a response variable cannot be distinguished from each other Signup and view all the answers

Match the following concepts with their focus:

Sampling Procedure = Method for choosing individuals for a sample Cluster Random Sample = Divides population into clusters for sampling Stratified Random Sample = Samples from defined strata of a population Simple Random Sample = Ensures every individual has equal chance of selection Signup and view all the answers

Match the following terms with their relevance to experimental design:

Experiment = Subjects assigned to certain conditions to assess causal links Randomization = Process to eliminate bias in sample selection Control Group = Group that does not receive treatment for comparison Treatment Group = Group that receives the experimental intervention Signup and view all the answers

Match the following statements with the type of variable they describe:

Explanatory Variable = Expected to explain changes in a response Response Variable = Outcome that is measured in a study Confounding Variable = Complicates the interpretation of results Lurking Variable = Hidden factor that may influence the observed variables Signup and view all the answers

Study Notes

Study Notes on Statistical Methods

Individual: A single unit evaluated in a study.
Population: All individuals of interest in a study.
Sample: A subset of the population, made of individuals from the population of interest.
Variable: A characteristic of individuals. Different individuals may have different values.
Statistic: A numerical summary of values from a sample. Examples include mean, median.
Parameter: A numerical summary of values for the entire population. Usually unknown and estimated from a sample.
Experiment: Subjects are assigned to different conditions/treatments (interventions) to find causal links.
Observational Study: Values of variables are observed to determine relationships without manipulation. Used when experiments are unethical or impractical.
Prospective Study: Follows subjects into the future to observe how variables change.
Retrospective Study: Looks back in time to observe variables and how they were related in the past.
Response Variable: Measures outcome or result of interest.
Explanatory Variable: A variable thought to explain changes in the response variable.
Comparative Study: Compares variables and conditions to determine cause and effect relationships.
Sampling Procedure: Method for selecting individuals for a sample.
Sampling Bias: Systematic tendency to exclude certain types of individuals.
Nonresponse Bias: Occurs when individuals chosen for a sample do not respond, often due to disinterest or insecurity.
Response Bias: Occurs when individuals respond inaccurately or falsely to questions, potentially due to insecurity, poorly worded questions, or question order.
Probability Sample: Selected using probability methods, ensuring each individual has a known chance of selection.
Convenience Sample: Selected for convenience, not based on a probability method.
Simple Random Sample: Each possible sample of the chosen size has the same probability of being selected.
Stratified Random Sample: Population divided into groups (strata), then a random sample from each stratum.
Cluster Random Sample: Population divided into groups (clusters), then a random sample of clusters, and all individuals in the selected clusters are included.
Lurking Variable: A variable influencing the relationship between variables in a study but not studied directly.
Confounding Variable: Effects of two variables on a response cannot be distinguished, among explanatory or lurking variables.
Randomized Comparative Experiment: An experiment that compares effects of treatments with random assignment of subjects to treatments. This reduces potential bias in treatment assignment.
Treatment Group: Individuals receiving the treatment.
Control Group: Individuals receiving a standard treatment or no treatment.
Blinding: Method where subjects do not know group assignment (single-blind) or subjects and researchers do not know assignment (double-blind).