Basic Vocabulary
When certain responses are favored.
Bias
When an individual chosen for a sample cannot be contacted, or refuses to participate.
Nonresponse Bias
When every population member has an equal chance of being selected.
Simple Random Sampling
Used to compare results, always stays the same.
Control
A "fake" treatment is given. Used to see if there are real results with the actual treatment.
Placebo
When individuals give false answers.
Response Bias.
Individuals are chosen from the population dependent upon availability.
Convinience Sampling
When the subjects and the people experimenting do not know what treatment the subjects received.
Double-Blind
An experimental condition given to the subjects.
Treatment
When the wording of a question may create a misunderstanding, leading to incorrect responses from individuals
Question Wording Bias
Every nth person is chosen.
Systematic Sampling
Treatments are imposed and cause & effect can be inferred.
Experiment
Individuals on whom the experiment is being performed.
Experimental Units
Individuals with stronger opinions will be more likely to respond than those who do not.
Voluntary Response
The population is sampled proportionally based on strata.
Stratified Sampling
When each experimental unit receives both treatments.
Matched Pairs
Treatments are not imposed, but generalizations about the population can be made.
Observational Study
Bias occurs when a population or a select group of people is not represented.
Undercoverage Bias
Dividing the population into different groups, then selecting a single group from the population.
Cluster Sampling
What features does a well-designed experiment have? (Four Things)
1. Comparison
2. Random Assignment
3. Replication
4. Control