Information for teachersThis PowerPoint presentation gives some

examples of analysis statements.Students own answers will differ based on

their choice of investigative question.This PowerPoint is editable so can be

changed to suit the wording you choose to use with your class.

Further sample analysis statements (especially at Excellence level) can be found in the assessment schedule.

www.education.nzta.govt.nz

AS 1.10 Maths and statistics Driven to distraction- Analysis section

Writing analysis statementsYou need to write statements about what

you observe in your graphs and from your summary statistics about the distributions.

Statements must be comparative, i.e. The statements must compare the distributions for the numerical variable for the two groups.

Statements must use correct statistical terms and include values (evidence).

Aim to write five comparative statements about what you notice about your data.

Features of distributionsLook for the following features:

◦ shape, ◦ middle 50%, ◦ shift, ◦ overlap, ◦ spread, ◦ unusual or interesting features.

What do you notice?

Tired vs Reaction Time - centreThe box and whisker graph

shows that the centre of the distribution of reaction times (median) for those that are tired is longer at 393 ms than for those who are not tired (294 ms).

Category

Min LQ Median

Mean

UQ Max

NotTired

177 227 294 312 386 501

Tired 220 299 393 417 557 598

Texting vs Reaction Time - centre

Write your own statement similar to the one on the previous slide

Category

Min LQ Median

Mean

UQ Max

NotText 177 227 263 279 300 457

Text 287 381 458 460 557 598

Tired vs Reaction Time - spreadThe interquartile range for the

reaction times for those who are not tired (159 ms) is almost 100 ms less than the interquartile range of reaction times for those who are tired (258 ms). This means that there is more spread for the middle 50% of reaction times for those who are tired than for those students who are not tired.Categor

yMin LQ Media

nMean

UQ Max

NotTired

177 227 294 312 386 501

Tired 220 299 393 417 557 598

Texting vs Reaction Time - spread

Write your own statement similar to the one on the previous slide

Category

Min LQ Median

Mean

UQ Max

NotText 177 227 263 279 300 457

Text 287 381 458 460 557 598

Tired vs Reaction Time - overlap I can see from the box and whisker

graph that there is some overlap of the middle 50% of reaction times for those that are tired with the middle 50% of reaction times for those that are not tired. The lower quartile for the reaction times for those that are tired (299 ms) is slightly slower than the median reaction time for those students who are not tired (294 ms). This tells me that at least 75% of reaction times for students that are tired are slower than the fastest 50% of the reaction times for those students who are not tired.Categor

yMin LQ Media

nMean

UQ Max

NotTired

177 227 294 312 386 501

Tired 220 299 393 417 557 598

Texting vs Reaction Time - overlap

Write your own statement similar to the one on the previous slide

Category

Min LQ Median

Mean

UQ Max

NotText 177 227 263 279 300 457

Text 287 381 458 460 557 598