stat quiz 1

categorical

divides a case into groups

quantitative

records the amount or degree of something for each case with measurements units

identifier variable

a variable used to uniquely identify the individual/case

ordinal variable

variable that reports order without natural unitsex

explanatory variable

variable that explains why the result happened

response variable

variable that shows the results

population

includes all individuals or objects of interest

sample

subset of cases from population

statistical interference

process of using data from a sample to gain info about the population

sampling bias

occurs when the method of selecting a sample causes the sample to differ from the population in some relevant way

random sample

sampling that is random

association

if values of one variable tend to be related to values of the other variable

confounding variable

third variable thats associated with both the explanatory and response variableob

observational study

researcher does not actively control the value of any variable but simply observes the values as they naturally exist

experiment

a study in which the researcher actively controls one or more of the explanatory variables

randomized experiment

the explanatory variable for each unit is determined randomly, also eliminates confounding variables

control group

group that thinks they are getting the same the treatment as the experiment group

placebo effect

people believe they are getting the same treatment as the experiment group