AP STATS Chapter 4 Vocab

249994613	population	the entire group of individuals about which we want information
249994614	sample	the part of the population from which we actually collect information
249994615	convenience sample	interviewer chooses individuals who are easiest to reach
249994616	bias	occurs when the design of a study systematically favors certain outcomes
249994617	voluntary response sample	consists of people who choose themselves by responding to a general appeal
249994618	simple random sample (SRS)	is chose so that every set of n individuals has an equal chance to be the sample already selected
249994619	table of random digits	a long string of digits such that each entry in the table is equally likely to be any of the 10 digits 0-9 and the entries are independent of each other
249994620	stratified random sample	an SRS is chosen groups of similar individuals called strata
249994621	cluster sample and clusters	divide the population into smaller groups which mirror the characteristics of the population. Then an SRS of the clusters is chosen
249994622	strata	are similar within, but different between
249994623	clusters	are similar between but different within
249994624	inference	the process of drawing conclusions about a population on the basis of sample data
249994625	sampling frame	the list of individuals from the sample is drawn
249994626	undercoverage	occurs when some groups in the population are left out of the sampling process
249994627	nonresponse	occurs when a chosen individual can't be contacted or refuses to participate
249994628	response bias	a systemic pattern of incorrect responses in a sample survey
249994629	observational study	observes individuals and measures variables of interest
249994630	experiment	deliberately imposes some treatment on individuals to measure their responses
249994631	lurking variable	a variable that is not among the explanatory or response variables in a study but that may influence the response variable
249994632	confounding	occurs when two variables are associated in such a way that their effects on a response variable cannot be distinguished from each other
249994633	treatment	specific condition applied to the individuals in an experiment
249994634	experimental units	the smallest collection of individuals to which treatments are applied
249994635	subjects	human experimental units
249994636	factors	explanatory variables
249994637	random assignment	experimental units are assigned to treatments using a chance process
249994638	completely randomized design	the treatments are assigned to all the experimental units completely by chance
249994639	control group	provides a baseline for comparing the effects of the other treatments
249994640	replication	using enough experimental units to be sure that results did not happen by chance
249994641	placebo effect	the response to a dummy treatment
249994642	double-blind experiment	neither the subjects nor those who interact with them and measure the response variable know which treatment a subject received
249994643	single-blind experiment	the subjects are unaware of which treatment they are receiving, but the people interacting with them and measuring the response do know
249994644	statistically significant	an observed effect so large that it would rarely occur by chance is
249994645	block	a group of experimental units that are known before the experiment to be similar in some way that is expected to affect the response to the treatments
249994646	randomized block design	the random assignment of experimental units to treatments is carried out separately within each block
249994647	matched pairs design	blocks are created by matching pairs of similar experimental units