# Summary of key words

Population

=

All

Census

=

A survey of the whole population

Sampling

=

Representation

Bias

=

A systematic error in a survey that can influence and skew the outcome of the data towards a certain direction

Random sampling

=

Equal chance examples include simple random sampling and stratified sampling

Stratified sampling

=

Sample every category

Cluster sampling

=

Everything in a couple of categories (also known as one-stage)

Multi-stage sampling

=

Sampled samples (also known as two-stage)

Leading question

=

A question that guides the respondent to answer in a particular way

Opportunity sampling

=

Immediately available

Voluntary sampling

=

Volunteers give their views

Systematic sampling

=

Select every Kth subject