# Level 1

## 91036: Investigate bivariate numerical data using the statistical enquiry cycle

Updated May 2019. The section headed ‘Required quality of student response’ has been updated.

### Problem

For this standard, students will be working with a relationship question they have been given.

### Plan and Data

The standard requires students to plan the investigation and collect all their own data for analysis. The planning and data collection may be carried out in small groups (2 or 3) or individually.

In their plan students need to indicate what variables they will measure and describe how they will measure them. The description needs to include discussion on possible sources of variation in the measurements and actions they will take to ensure the data they collect is consistent. It is appropriate to give students an opportunity to review their plan with the teacher before data collection occurs.

If students are collecting and gathering data from websites, care should be taken to ensure that there is an opportunity for students to manage variation. For example, if a student is investigating whether the value of a car is a good predictor of the odometer reading and is collecting the data from Trade Me, there is an opportunity to manage variation because of the variety of ways in which the value of the car is given on the Trade Me website. A similar opportunity is not available for data on the Census at School website.

### Analysis

When commenting on features of the visual display(s), students need to discuss what they can see in the display(s), rather than what they cannot see in the display(s). Students need to be careful not to classify points as unusual/oddities/outliers without appropriate justification.

### Conclusion

Students need to communicate relationship(s) in the data in context, for example ‘students in Year 11 in my school who have longer legs tend to jump further.’

### Required quality of student response

At Achieved, students need to provide evidence of using each component of the statistical enquiry cycle detailed in Explanatory Note 3 of the standard.

Merit is with justification, and students need to link components of the statistical enquiry cycle to the context. The justification comes from providing supporting statistical evidence from the displays for any findings communicated in the student response.

Excellence is with statistical insight, and students need to integrate statistical and contextual knowledge throughout the statistical enquiry cycle. They need to have an understanding about the context, and are expected to demonstrate that they have thought about the process they have undertaken and their findings.