A census is conducted when every element in the population is included.
Sampling occurs when data are collected from a group selected from the bigger population.
It is more economical to collect data from a sample than to collect data from the whole population.
Bias can be introduced by:
- relying on a sample of 'one' that reflects a personal opinion, which is often based on limited experiences
- selecting a sample that is too small and not representative of the bigger population.
