Year level: 8

Strand: Statistics

Lesson length: 60 mins

Students will plan and conduct a statistical investigation to find the average height of students at their school. In this lesson of the Are you average? lesson sequence, students learn about the ethics of collecting data, whether or not random samples represent a population, size of sample and conducting surveys.

This lesson is one of a series of lessons that can be used to assist students to plan and conduct a statistical investigation.

### Achievement standard

Students conduct statistical investigations and explain the implications of obtaining data through sampling. Students analyse and describe the distribution of data. They compare the variation in distributions of random samples of the same and different size from a given population with respect to shape, measures of central tendency and range.

### Content descriptions

Students learn to investigate techniques for data collection including census, sampling, experiment and observation, and explain the practicalities and implications of obtaining data through these techniques. AC9M8ST01

They plan and conduct statistical investigations involving samples of a population; use ethical and fair methods to make inferences about the population and report findings, acknowledging uncertainty. AC9M8ST04

### General capabilities

Numeracy

• Interpreting and representing data (Level 7)

Digital Literacy

Ethical understanding

• Exploring ethical issues (Level 5)

Critical and creative thinking

• Draw conclusions and provide reasons (Level 5)
• Develop questions (Level 5)
• Identifying, processing and evaluating information (Level 5)

Related content

Digital technologies (AC9DI8P02)

The following mid-sequence on-going assessment is suggested below.

• Monitor student progress and cooperation.
• Engage with students who need support or encouragement. Consider those students who may struggle with the next lesson that includes analysis and communication as to whether further scaffolding is required.
• Assign (if you haven’t already) or collect answers from the selection of questions given to students at the end of the previous lesson: Are you Average? (Part 1).

It is expected that students have:

• a basic understanding of statistics and data sampling
• familiarity with terms: sampling, representative, random choice, population, survey.

Some students may:

• use sampling methods that affect accuracy and demonstrate underestimating and bias
• think that statistical investigation requires data from the entire population
• believe that statistical investigations always have a clear answer
• have difficulty creating graphs and calculating summary statistics using technology.

To address the areas of challenge, the following suggestions are below. Teachers can:

• emphasise the importance of choosing appropriate sampling methods, use examples to demonstrate the impact on accuracy, highlight pros and cons of different methods, and engage students in comparing outcomes with different sampling methods
• explain the difference between population and sample, highlight the impracticality of collecting data from the entire population and provide examples of investigations using samples, for example, market research versus census
• highlight the uncertainty and variability in statistical investigations, explain that conclusions are based on probabilities and can vary with samples, engage students in analysing results with consideration for uncertainty
• use group structures to leverage a wider range of skills and knowledge, source easy guidance videos, use an excel template with pre-coded stats and graphs.

## What you need:

• Lesson plan (Word)

• Teacher's slides (PowerPoint)

• Teacher's notes and examples (Word)

• Are you average template (Excel)

• Measuring tapes, digital devices (tablets or computers)