Statistical Investigations: Level 5

The key idea of statistical investigations at level 5 is telling a story about the wider universe with supporting evidence.

Students are building on the ideas from level four about different aspects of the PPDAC (Problem, Plan, Data, Analysis, Conclusion) cycle.  The key transition at this level is the acknowledgement that samples can be used to answer questions about populations.

Students will be posing investigative questions about populations and using samples to answer these.

Students need to realise that the data collected may have to be cleaned.  To help with this they should be familiar with the survey questions posed, who the data was collected from and how the data was collected.  Once data is identified as needing cleaning, strategies on how to do this should be discussed, for example, whether the value removed, or “cleaned”. 

Students may need to recategorise data into broader categories or smaller categories depending on the question they are trying to answer.  They will be looking at patterns and trends in displays and using these to answer their investigative question.  Thinking routines such as: “What information can you get from this plot?” and “What evidence do you have for saying that?” will be helpful for students.

Students will be starting to use informal methods to make comparisons between sample distributions using box plots and growing their reasoning about sampling variability, shape, spread, unusual and interesting features, and making a call. See CensusAtSchool 2009 Teachers Day. 

This key idea develops from the key idea of statistical investigations at level 4 where students are telling a class story in detail with supporting evidence.

This key idea is extended in the key idea of statistical investigations at level 6 where students are telling a story about a wider universe taking variation and uncertainty into account.