The tendency of subjects to show a response even when administered a placebo.
Placebo Effect
A list of individuals from whom the sample is drawn.
Sampling Frame
The sequence of several components representing events that we are pretending will take place.
Trial
The subjects or objects upon which an experiment is conducted.
Experimental Units
Bias introduced when a large fraction of those sampled fails to respond.
Nonresponse Bias
The specific values or conditions of a factor in an experiment.
Level
A (representative) subset of a population, examined in hope of learning about the population.
Sample
A study that asks questions of a sample drawn from some population in the hope of learning something about the entire population. Polls taken to assess voter preferences are common examples of this.
Sample Survey
The entire group of individuals or instances about whom we hope to learn.
Population
To be valid, an experiment must assign experimental units to treatment groups at random.
Random Assignment
Gathering similar experimental units into blocks to isolate variability attributable to differences between blocks.
Blocking
When an observed difference is too large to believe it occurred naturally.
Statistically Significant
A sampling scheme that biases the sample in a way that gives a part of the population less representation than it has in the population suffers from this.
Undercoverage
The best defense against bias is ____________________, in which each individual is given a fair, random chance of selection.
Randomization
The outcomes measured in an experiment to determine the effect of treatments.
Response
Anything in a survey design that influences responses falls under the heading of __________________.
Response Bias
An outcome is ______________ if we know the possible values it can have, but not which particular value it takes.
Random
A design where subjects are randomly assigned to treatments only within blocks.
Randomized Block Design
A sample that consists of the entire population is called a _____________.
Census
A treatment known to have no effect, administered to one group to compare with other treatments.
Placebo
Any systematic failure of a sampling method to represent its population is ___________.
Bias
When the levels of one factor are associated with the levels of another factor in such a way that their effects cannot be separated.
Confounding
Comparing subjects who are similar in ways not under study to reduce unwanted variation.
Matching
A variable whose levels are manipulated by the experimenter.
Factor
These are hard to generate. Nevertheless, several Internet sites offer an unlimited supply of equally likely ____________________.
Random Numbers
Bias introduced to a sample when individuals can choose on their own whether to participate in the sample.
Voluntary Response Bias
An experiment where everyone in both classes (subjects and evaluators) is blinded.
Double-blind
The process, intervention, or controlled circumstance applied to randomly assigned experimental units.
Treatments
Values of the __________________ record the results of each trial with respect to what we were interested in.
Response Variable
Sampling schemes that combine several sampling methods.
Multistage Sample
A sampling design in which the population is divided into several subpopulations, or strata, and random samples are then drawn from each stratum.
Stratified Random Sample
A _________________ of sample size n is a sample in which each set of n elements in the population has an equal chance of selection.
Simple Random Sample
A sampling design in which the population is divided into clusters, and entire clusters are randomly selected.
Cluster Sample
A sample drawn by selecting individuals systematically from a sampling frame.
Systematic Sample
A small trial run of a survey to check whether questions are clear.
Pilot Study
A ___________________ consists of the individuals who are conveniently available.
Convenience Sample
A design where all experimental units have an equal chance of receiving any treatment.
Completely Randomized Design
this models a real-world situation by using random-digit outcomes to mimic the uncertainty of a response variable of interest.
Simulation
A numerically valued attribute of a model for a population.
Population Parameter
A sample is said to be __________________ if the statistics computed from it accurately reflect the corresponding population parameters.
Representative
manipulates factor levels to create treatments, randomly assigns subjects to these treatment levels, and then compares the responses of the subject groups across treatment levels.
Experiment
The number of individuals in a sample. It determines how well the sample represents the population, not the fraction of the population sampled.
Sample Size
An experiment where individuals in one class (subjects or evaluators) are blinded.
Single-blind
,__________________ are values calculated for sampled data.
Statistic or Sample Statistic
A component uses equally likely random digits to model simple random occurrences whose outcomes may not be equally likely.
Simulation Component
The natural tendency of randomly drawn samples to differ, one from another. Sometimes, unfortunately, called sampling error, it is just the natural result of random sampling.
Sampling Variability
When individuals associated with an experiment are not aware of how subjects have been allocated to treatment groups.
Blinding
The experimental units assigned to a baseline treatment level for comparison.
Control Group
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