Planning tool

Students:

• define different methods of data sampling, question the effect on results for each and can comment on the advantages and disadvantages of each
• ask questions to interrogate visualisations of data presented in media, reports and summaries
• question whether choices of representation are in line with particular points of view
• can discuss the aspects of the data that was chosen to be represented or not represented.

Some students may:

• find it difficult to imagine or consider whether reported data in the form of a visualisation or chart best communicates the context for which it was created.
• underestimate that poor visualisations exist in a range of media and take these at face value.
• not question what a visualisation is showing and misinterpret the data display.
• not take in the details of data displays, such as scales or title, or may not consider what has been excluded.
• underestimate that different sampling methods affect the results and how data is represented, and therefore misrepresents real data.
• not realise that taking an accurate and valid sample is very difficult. Ask students how they would account for the vast diversity in their own school if they were to conduct a whole-school investigation.

The Learning from home activities are designed to be used flexibly by teachers, parents and carers, as well as the students themselves. They can be used in a number of ways including to consolidate and extend learning done at school or for home schooling.

Learning intention

• We are attempting to sample the Australian population using a variety of methods.
• We are learning to compare each sample for its advantages and limitations.

Why are we learning about this?

A census is only conducted every five years and there’s a good reason for that. It’s extremely challenging to accurately count the entire population. Almost all the data analysis we are presented with is based on samples. The validity of these samples contributes greatly to the overall usefulness and accuracy of the data. By more deeply understanding how samples are generated, we can better assess whether a sample for a given study accurately reflects the population it intends to make inferences about.

What to do

1. Develop a strategy for producing a valid random sample for the Australian population using each of the strategies below. You don’t need to produce the sample, although you could set yourself a big challenge and try!
2. For each sampling method, describe in detail how you could create a sample size of 1,000.
3. Use the table below as a guide.

Success criteria

• I can define and compare different sampling methods.
• I can attempt to sample the Australian population using a variety of methods.