Maths

• Population: the total set of possible values that could be selected for the sample
• Sampling Unit: a single member of the population
• Sample: a selection of sampling units observed from the population on which analysis is carried out in order to make conclusions about the population as a whole
• Sampling Frame: a numbered list of all members of the population
• A simple random sample of size n is one where very sample of size n has an equal chance of being selected
• Quota Sampling: an interviewer or researcher selects a sample that reflects the characteristics of the whole population
• Opportunity Sampling: taking the sample from people who are available at the time the study is carried out and who fit the criteria you are looking for
• Random Sampling: simple random sampling, stratified sampling, systematic sampling
• Census: all members of the population are observed
• Simple Random Sampling: use a sample frame to assign a number 1 to N to each member of the population. Use a random number generator to generate integers between 1 and N, select the population member assigned to each number generated to form the sample ignoring any repeated values until n members of the population have been selected as the sample.
• Simple Random Sampling: each sampling unit has an equal chance of being selected for the sample
• Stratified Sampling: population is divided into mutually exclusive strata and a random sample is taken from each
• Systematic Sampling: members of the population are selected at regular intervals from the sampling frame. The first sampling unit is chosen at random and this ensures that each member of the population is equally likely to be selected.