vocab bruh Flashcards
population
entire group of individuals we want information about
census
collects data from every individual in the population
sample
subset of individuals in the population from which we actually collect data
How big must the population be compared to the sample?
10x
bias
consistently underestimates or consistently overestimates the value you want to know
convenience sample
choosing individuals from the population who are easy to reach, results in a convenience sample
random sampling
involves using a chance process to determine which members of a population are included in the sample
simple random sample (SRS)
every group of individuals in the population has an equal chance to be selected as the sample
stratified random sample
classify population into groups of similar individuals and strata
cluster sample
classify population into groups of individuals that are located near each other
voluntary response sample
consists of people who choose themselves by responding to a general invitation
inference
the process of drawing conclusions about a population on the basis of sample
observational study
observes individuals and measures variables of interest but does not attempt to influence the responses
experiment
deliberately imposes some treatment on individuals to measure their responses
confounding
when two variables are associated in such a way that their effects on a response variable cannot be distinguished from each other
treatment
a specific condition applied to the individuals in an experiment
experimental units
the smallest collection of individuals to which treatments are applied
double- blind experiment
neither the subjects nor those who interact with them and measure the response variable know which treatment a subject received
a statistically significant association in data from a well- designed experiment implies what?
causation
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
randomized block design
random assignment of experimental units to treatments is carried out separately within each block
matched pairs design
randomized block experiment in which each block consists of a matching pair of similar experimental units
What type of inference can be made from randomly selecting individuals?
inference about population
What type of inference can be made from randomly assigning groups?
cause and effect
difference between stratified random sample and blocks
a way to get subjects for block or random assignment, how you get groups. and then random assignment
