Sampling

Sampling

Populations and samples

• The population refers to a large group of individuals that the researcher may be interested in studying-target population
• For practical/economic reasons, it is usually not possible to include all members of a target population so a researcher selects a smaller group-sample
• Ideally, the sample will be representative of the target population so that generalisation of findings becomes possible
• However, the vast majority of samples contain some degree of bias

Random sample

• A random sample is a sophisticated form of sampling in which all members of the target population have an equal chance of being selected
• A complete list of members of the target population is obtained
• Then all the names on the list are assigned a number 
• The sample is generated through use of a lottery method

+Free from researcher bias, cannot select people they think will support their hypothesis

-Time consuming and difficult to conduct

-May still have an unrepresentative sample

-Selected ppts may refuse to take part

Systematic sample

• When every nth member…