Sampling methods

Where every sample of a size has an equal chance of being selected

Random number generator

Pro: Easy and cheap

Con: Not suitable when the population size or sampling size is large, sampling frame is needed

The required elements are chosen at regular intervals from an ordered list

Pro: Suitable for large samples and large populations

Con: Sample frame is needed

Population is divided into mutually exlusive strata

Pro: Gurantees proportional representation of groups within a population

Con: Population must be clearly classified into distinct strata

Population sampled is required on who is available at the time or willingness to take part

Pro: Easy

Con: Can be bias

Method used by market researchers who go to the public and ask a certain amount of people about a topic

Pro: Easy 

Con: The chosen sample may not be representative of other characteristics that weren't considered

Observing every member of a population

Pro: Exremely accurate

Con: Time consuming