Census, Samples and Data Collection

A census collects data from every member of a population, while a sample collects it from only some of them. This NSW Year 8 maths subtopic (NESA outcome MA4‑DAT‑C‑02) looks at how data is gathered and how far the results can be trusted.

You will decide when a sample makes more sense, tell primary from secondary data, choose between a survey, an observation and an experiment, and select random, systematic and proportional samples. You will estimate a count for a whole school from a sample, estimate the fish in a dam by tagging, and spot bias in an online poll or in a survey taken at the old skate park. It is part of Year 8 Investigating Data.