Sampling
A type of sampling that is analogous to a lottery.
Simple random sample
The title of a book. Is this a qualitative or quantitative variable?
Qualitative variable
A study when the assignment of treatment isn't made by the investigator.
Observational study
_______ is a subset of a population, containing individuals that are actually observed.
Sample
Every third day, a computer network administrator analyzes the company's network logs to check for signs of computer viruses. What kind of sampling is this?
Systematic sampling
The number of classes taken. Is this a qualitative or quantitative variable?
Quantitative variable
A study hen an investigator assigns the treatments to the experimental units.
________ variables are always numerical.
Draw a sample of eight animals by drawing a simple random sample of two animals from each group. What kind of sample is this?
Stratified sampling
The number of steps in a stairway. Is this an example discrete or continuous variable?
Discrete variable
Which experiment is defined as neither the experimenter nor the subjects know which treatment has been assigned to which subject?
Double-blind experiment
When experimental units are people, they are called ________.
Subjects
An airline company wants to survey its customers one day, so they randomly select 5 flights that day and every passenger on those flights. What kind of sampling is this?
Cluster sampling
The name of countries. Is this an example of ordinal or nominal variable?
Nominal variable
What are the two types of observational studies?
Cohort and case-control study
In a _______ study, the subjects are followed over time.
Prospective
A retailer samples 25 receipts from the past week by numbering all the receipts, generating 25 random numbers, and sampling the receipts that correspond to these numbers. What kind of sampling is this?
Simple random sample
The number of students enrolled at a college. Is this an example of discrete or continuous variable?
Continuous variable
In a study conducted at University of Southern California, J. Peters and colleagues studied elementary school students in 12 California communities. Each year for 10 years, they measured the respiratory function of the children and the levels of air pollution in the communities. Was this a cohort or case-control study?
A _______ sample is one in which the population is divided into groups and a random sample is drawn from each group.
Stratified sampling