Random sampling
The process of using chance to select individuals from a population to be included in the sample.
Simple random sampling
In a population of size N is obtained through...
If every possible sample of size 'n' has an equally likely chance of occurring, it is called...
Frame
A list of all the individuals within the population on interest
Random Number Tables
To generate a simple random sample, use...
Sample without replacement
Once an individual is selected to be in a sample, he or she is removed from the population and cannot be chosen again.
Sample with replacement
A selected individual is placed back into the population and so could be chosen a second time.
Seed
In a random-number generator, the seed is the initial point in the table of random numbers. The seed can be any non-zero number.
Stratified sample
Obtained by separating population into homogeneous, non-overlapping groups called ...
then obtaining a simple random sample from each group.
The individuals within each stratum should be homogeneous (or similar) in some way.
Systematic sample
Obtained by selecting every 'kth' individual from the population. The first individual corresponds to a random number between 1 and k.
Cluster sample
Obtained by dividing the population into heterogeneous, non-overlapping groups called ...
selecting all individuals within a randomly selected collection or group of individuals.
The individuals within each group should be heterogeneous (or different) in
Convenience sample
A sample in which the individuals in a sample are easily obtained and not based on randomness.
Self-selected / voluntary response
A type of convenience sample where individuals themselves decide to participate to be in the sample.