PSY285 Sampling examples (khan academy)

A restaurant leaves comment cards on all of its tables and encourages customers to participate in a brief survey to learn about their overall experience.

Voluntary response sampling

A truck manufacturer selects 333 trucks at random from each of 666 models for safety testing.

Stratified random sample

A manager associated each employee's name with a number on one ball in a container, then drew balls without looking to select a sample of 555 employees.

simple random sampling

A teacher puts students' names in a hat and chooses without looking to get a sample of 333 students. What type of sample is this?

simple random sampling

Employees at a website want to select a sample of their users to ask for a donation. They randomly select one of the first 252525 user each day and show them a message asking for a donation. They also show the message to every 25^\text{th}25th25, start superscript, start text, t, h, end text, end superscript user from that point on

! Systematic random sample

An airline company wants to survey its customers one day, so they randomly select 555 flights that day and survey every passenger on those fligh

! cluster sampling

A quality control worker at a factory selects the first 101010 items she sees as her sample for the day.

Convenience sampling