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NZAMT NZQA NZ Grapher NZ Maths Census at School Study It

3.9 Bivariate HOME | Achievement Objectives | Overview | Data sets & Variable Types | Introduction | Scatter plots | Excel | iNZight | Correlation Coefficient & Linear Model | The effect of Groups & Unusual Values | Predictions | Causality | Non-Linear Models | Discussion & Conclusion | Report Writing

3.9 Investigate Bivariate Data AS91581

Possible Lesson Sequence for AS 3.9 Bivariate Data (AS 91581)

Class site

1. Introduction & Overview - What is Bivariate Data? Posing an investigative question (Achievement Objectives)
2. Investigating data sets and variable types - explanatory & response
3. Writing an introduction: Investigative Question, Variables Defined, Background context, Research, Units...
4. Scatter plots, visual interpretation & describing any relationship
5. Making scatter plots using Excel & iNZight, Selecting a model & adding a 'line of best fit' with equation
6. Describing the type, association, strength & features of the relationship and relating this to the context.
7. Correlation Coefficient r and trend line
8. The effect of Groups & Outliers on 'r'
9. Making a prediction using the model.
10. Correlation & Causation
11. Non-linear models
12. Discussion & writing a Conclusion
13. Class example: data set, question, variables
14. Class example: Scatter plot & discussion
15. Class example: Predictions & discussion
16. Class example: Conclusion (extension: Residuals)
17. Peer critique & feedback on Class example
18. Assessment context & research, Report Writing, Assessment checklist (Class notes)
19. Assessment time
20. Assessment time

For Teachers

* Be familiar with the Achievement Standard AS3.9 91581 (link to NZQA)

* Check the latest information on the NZQA clarifications page as things change all the time, and the exemplars in NZQA may be out of date (as they are in this standard)

* Look over the NZQA Exemplars on AS 3.9 Bivariate Data AS3.8 A & AS3.8 B Note: these exemplars may not reflect the latest clarification information.

* Material available on the mathstatsfacilitators web site AS3.9 page

* AS 3.9 page at CENSUS at schools site.

* Check the latest comments on the NZmaths forum (login required)

* Any further ideas / suggestions / resources/ comments / errors. Please email

* AS 3.9 section on Nayland Web site updated: Oct 2013


AS3.9 (91581) Carry out investigations of phenomena, using the statistical enquiry cycle:
- posing an appropriate relationship question using a given multivariate data set (The investigative question needs to be an appropriate one it is expected that a purpose for the investigation is evident)
- selecting and using appropriate displays
- identifying features in data
- finding an appropriate model
- describing the nature and strength of the relationship and relating this to the context
- using the model to make predictions
- using informed contextual knowledge and statistical inference
- communicating findings and evaluating all stages of the cycle and in a conclusion.

Link to iNZight siteUsing iNZight or Excel to do the 'data crunching' and producing graphs

Check out the iNZight tips and tricks page.

Remember: The Focus is on the statistical cycle and the discussion and interpretation of the analysis.


Other Useful Links for AS3.9 Bivariate Data (AS 91581)

Pricilla Allan's Wiki | powerpoints |

Census at schools resources page | NZ Stats info share | Statistics NZ Bivariate example

McD's unit on Census & School | NZ incomes | Data sets with source and variable info for investigations. (and other data sets)

Ross Parsonage Video (link to census at schools)

Data Sets: | multivariate | Data Story Library | ConnectMV


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