Statistical Investigations: Level 3

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The key idea of statistical investigations at level 3 is telling the class story with supporting evidence.

Students are building on the ideas from level two and their understanding of different aspects of the PPDAC (Problem, Plan, Data, Analysis, Conclusion) cycle.  Key transitions at this level include posing summary investigative questions, and collecting and displaying multivariate and time series data.

Summary or time series investigative questions will be posed and explored.  Summary investigative questions need to be about the group of interest and have an aggregate focus.  For example, what are typical numbers of children in a family for students in our class?  What types of fruit do students in our class like?

Data displays build on the frequency plots from level two and can be formalised into dot plots and bar graphs.  Students should be encouraged to show a second variable, for example, by using colour.  They may like to look at boys and girls fruit preferences.

Students will be making summary statements, for example, the most common number of  children in a family for our class is three, nine students have three children in their family (read the data), or most students (16 students out of the 27 in our class) have between two and four children in their family (read between the data).

Teachers should be encouraging students to read beyond the data by asking questions such as: “If a new student joined our class, how many children do you think would be in their family?” 

This key idea develops from the key idea of statistical investigations at level 2 where students are learning to tell the class story.

This key idea is extended in the key idea of statistical investigations at level 4 where students are adding detail to their stories.