statistics summer 23

a subset of individuals in the population from which we collect data

a number that describes some characteristic of a sample

the entire group of individuals we want information about in a statistical study

a number that describes some characteristic of the population

a variable that assigns labels that place each individual into a particular group, called a category

a study in which researchers deliberately impose treatments on individuals to measure their responses

the science and art of collecting, analyzing, and drawing conclusions from data

an object described by a set of data. individuals may be people, animals, or things

any characteristic of an individual. a variable can take different values for different individuals

variable that takes number values that are quantities-counts or measurements

collects data from every individual in the population

a study that observes individuals and measures variables of interest but does not attempt to influence the response (no treatment)

sample of size n is chosen in such a way that every group of n individuals in the population has an equal chance of being selected as a sample

selects a sample by choosing an SRS from each stratum and combining the SRS’s into one overall sample

selects a sample by randomly choosing clusters and including each member of the selected cluster

selects individuals from a population who are easy to reach

allows individuals to choose to be in the sample by responding to a general invitation. for example, an online survey

involves using a random process to determine which members of a population are included in the sample

a treatment that has no active ingredient but is otherwise like other treatments

describes the fact that some subjects respond favorably to any treatment, even an inactive one (placebo).