When members of a sample cannot be contacted or refuse to respond, this is called _________________.
nonresponse
Some experiments give a ____________ (fake treatment).
placebo
True or false? Random selection allows us to make inferences about cause and effect.
False
True or false? Random selection allows us to make inferences about the population.
True
___________________ happens when some members of the population are left out or cannot be chosen for the sample.
undercoverage
True or false? Subjects are randomly placed in blocks.
False
This type of sample gives every possible sample of the same size the same chance of being selected.
Simple Random Sample
The four principles of experimental design are ______, _______, _____, and _____.
control, random assignment, replication, comparison
When the population is broken up into groups and a SRS is chosen from each group, this is called a __________________ sample.
stratified
When the population is broken up into groups and a SRS of groups is chosen and all of those group members are in the sample, this is called a _____________ sample.
cluster
In this type of design, experimental units are assigned to treatment groups completely at random.
Completely randomized design
Observational studies that track individuals into the future are called __________.
prospective
True or False? In a randomized block design, comparisons are made at the end of the experiment that compare one blocks results to other blocks results.
False
Each treatment is a combination of the levels of the __________variables (also called factors).
explanatory.
Observational studies that examine existing data are called ______________.
retrospective
In this type of design, experimental units that are similar with respect to a variable that is expected to have an affect on the response are grouped together.
randomized block design
A form of a randomized block design in which similar subjects are paired up into blocks and both treatments are randomly assigned to each person in the pair.
Matched pair design
Sampling methods sometimes lead to _________. This is when they are likely to overestimate or underestimate the value you want to know.
bias
In a __________sample, you choose individuals that are easiest to reach.
Convenience
When people lie in their responses, this is called ____________________.
response bias
Experiments impose one or more ______________.
treatments
__________ occurs when you cannot tell if the results are due to the explanatory variable or another lurking variable.
Confounding
The idea that different random samples of the same size from the same population will produce different results
Sampling variability
A census collects data from everyone in the ___________________.
population
_____________ means that neither the subjects nor those interacting with them know who is receiving each treatment.
double-blind
In an ____________ study, no treatment is administered.
observational
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