Evaluating Information Flashcards
What are statistics?
The science of collecting, organizing and interpreting data
The data that describes or summarizes something
What is a Statistical Population (referred to as population hereafter)?
The complete set of values
eg all the adult heights, measured to the nearest cm, of the human population
What is meant by sample?
A subset of the population
Used when it is impractical to measure the entire population (which is most of the time)
What are the Population Parameters?
The characteristics of the statistical population
What are Sample Statistics?
A summary of the data gathered from the sample
What is important about choosing a “Sample”?
MOST important step in any statistical analysis!
You want your sample to be representative of the population so that you can make inferences about the population
What is a Sampling Bias
When a studies design or conduct tends to favour certain results.
Examples of Bias:
- Choosing a sample from the basketball team to determine average height.
- Researcher has a personal stake on the outcome.
What is selection bias?
Researcher selects the participants
What is participation bias?
Participants volunteer to participate
What are 4 common sampling methods?
Simple Random
Systematic
Convenience
Stratified
What is a Simple Random Sample?
every member of population has a chance of being chosen
What is a Systematic Sample?
use a simple system (such as every 10th member of the population)
What is a Convenience Sample?
a sample that is convenient is chosen, (students of a particular class)
What is a Stratified Sample?
chosen from different subgroups or strata of the population. Within each strata simple random sampling is done.
What is a placebo?
a treatment meant to deceive a population into thinking they are receiving treatment.
What is a placebo effect?
A perceived or actual improvement in a condition even though the person was given no actual treatment to benefit them (the were given a placebo)