support for school statistics from statistics nz
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Support for School Statistics from Statistics NZ. [email protected] Statistics New Zealand Auckland Maths Assoc, University of Auckland Tue 25 Nov 08. Achievement objectives for today:. Participants will: Use Stats NZ resources to deliver curriculum objectives - PowerPoint PPT PresentationTRANSCRIPT
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Support for School Statisticsfrom Statistics NZ
[email protected] New Zealand
Auckland Maths Assoc, University of AucklandTue 25 Nov 08
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Achievement objectives for today:
Participants will:Use Stats NZ resources to
deliver curriculum objectivesFeel more confident and have more fun
with teaching the stats in Mathematics and Statistics in the NZ Curriculum
Find out (if time)what do (some Stats NZ) statisticians really do!
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Activities with www.stats.govt.nz:After an introductory ramble:Schools corner
StatZing!SURFs 1, 2, 3CensusAtSchool (a mention)
Table Builder (= TB); esp Census dataInfoshare:
Time series galoreHot Off The Presses (= HOTPs):
HOTPs and Statistical LiteracyQuickStats:
about your place etcThen: what do (some) statisticians really do!
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Curriculum and Stats NZ Resources 1:
The threads in the Stats and Probability strand:Statistical investigation
phenomena involving: multivariate (case) datasets time-series datasets
Statistical literacyreports with words, numbers, graphsrisk
Probabilitydistributionsdependence etc
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Curriculum and Stats NZ Resources 2:The threads … and resources for them:Statistical investigation Schools Corner,StatZing!
phenomena involving: HOTPs multivariate (case) datasets: SURFs,TB,CaS
time-series datasets: InfoshareStatistical literacy NZ in Profile
reports with Quickstats words, numbers, graphs: HOTPsrisk, relative risk: HOTPs, Tables
Probabilitydistributions: Tables dependence etc: Tables; 2 way
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Curriculum and Stats NZ Resources 3:Some are
designed for schoolsSome are
(a big one) inadvertently useful for schools!EG: The HOTPs (Hot Off The Presses):EG: a rich source of real (we hope) info:
New Zealand Income Survey: June 2008 quarter (a big one) Highlights | Commentary | Technical notes | Erratum | Tables |
Stat Literacy: Evaluate stat reports (L 6,7,8)
Statistical Enquiry Cycle: PPDAC … PPDAC … PPDAC … PPDAC … PPDAC …
Stat investigation: Story, Data Time series
Stat investigation: Methodology: defining questions, sampling methods, errors (samp and non) etc etc etc etc
Probability: One-way tables Two-way tables
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Why be nice to schools??Stats NZ: The World:
We need our clients to be informed & positiveSchool stats is a vital way to achieve this
Respondents: People Businesses
Users: Public Professional Technical
Dataset
Data
Information
DatasetDataset
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Two groups with converging interests:
TheOfficial Stats
sectorThe
Mathematics and Statistics Education Community
Vision: an informed society using statistics.
Curriculum: students will be: thinking mathematically and statistically; solving problems, modelling situations.
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A small problem:Unit-record multivariate datasets:Teachers need them!Official Stats agencies have lots but can’t release them!
Some smart solutions:CensusAtSchool (sort-of)SURFs for Schools: 1, 2, 3Tables by geographical Area
DatasetDataset
Dataset
SURF 1
SURF 2
SURF 3
Area Unit Males06 Females06 Tot06Henderson North 2,487 2,817 5,304Henderson South 1,956 2,070 4,023Tangutu 1,404 1,554 2,955Woodglen 2,013 2,193 4,203Glen Eden East 3,237 3,372 6,609New Lynn North 1,173 1,233 2,406New Lynn South 1,185 1,287 2,472
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Census at school 2009New dates:
3 March 2009 until 9 April 2009Register online:
http://www.censusatschool.org.nz/2007/register/If you have previously registered, OK.
Confirmation in November.Funded:
X% by Stats NZ(1-X)% by MoE
Expertise:Lots of it; from UoA
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New for 2009Teachers get their class results back
if they choose.Early in year so 2009 data
can be used for 2009 teaching.New questions: from consultations:
Dept of Stats UoA, MoE, Stats NZ, teachers nationwideQuestionnaire critiqued
by StatsNZ Questionnaire design team
www.censusatschool.org.nz
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1 Schools Corner: StatZing!, SURFs
2 Table Builder
3 Infoshare4 Releases by title: HOTPs
5 QuickStats
www.stats.govt.nz
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Find Info by/f
or …
StatZing! Latest Sec (Economics)
SURF 2
SURFs
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SURFs for Schools
Synthetic Unit Record Files:Multivariate datasets from Stats NZ surveys
1. Income supplement from the 2004 Household Labour Force Survey
2. 2001 Household Savings Survey3. Coming soon – 2006 Census
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2001 Household Savings Survey SURF
Based on a survey that collected information including income, assests, debt,net worth.
300 synthetic people representing the 5000+ people who responded to the survey.
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2001 Household Savings Survey SURF
Variables include:
–Gender–Employment–Qualification–Ethnicity–Partnered–Age
–Age of Partner –Total income–Wages/Salary income–Total debt–Total networth
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Using the SURF
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Teacher page for each activity
•Curriculum links
•Possible answers
•Available as a PDF document
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What can we improve?
For teachers For students
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Census: SURF 3
Under development; final checkingBased on
2006 Census of Population and DwellingsContains unit record datasets for each of New
Zealand’s 16 main Regional Authorities300 synthetic people who represent everyone
that responded for each region
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Census: SURF 3Variables included
– Sex – Work and Labour force status– Qualification– Ethnicity– Income– Age Group– Mode of transport to work– Hours worked– Cigarette smoking behaviour– Access to a cellphone/mobile phone– Access to the internet
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Preserved relationships
Variable Pers
onal
Inco
me
Wor
k an
d la
bour
fo
rce
stat
us
Sex
Qua
lific
atio
n –
high
est
Mai
n m
eans
of
trave
l to
wor
k
Hour
s w
orke
d in
em
ploy
men
t per
w
eek
Ethn
icity
Ciga
rette
sm
okin
g be
havi
our
Age
Acce
ss to
inte
rnet
Acce
ss to
a
Cellp
hone
/Mob
ile
Phon
e
Access to a Cellphone/Mobile Phone x x xAccess to internet x x xAge x x x x x x xCigarette smoking behaviour x xEthnicity x x x x xHours worked in employment per week xMain means of travel to work xQualification – highest x x xSex x xWork and labour force status
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Limitations: SURF 3: Census
Synthetic dataNot all relationships and patterns are preservedJoining tables together
does not represent the whole of New Zealand
However, you can compare regions!
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Battle for the ‘greener suburb’:an example using case data
Compare the ‘traveling to work’ habits of geographic areas.Which area has the ‘greener’ workers?
– Walking / Running / Cycling– Public transport– Carpooling???– Working at home?
(Graphic from CensusAtSchool)
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Battle for the ‘greener suburb’:where to find the data
We want a data source that contains information about modes of travel to work by area units.
Luckily, we have the 2006 Census of Population and Dwellings on Table Builder!
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2 Table Builder
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2006 Pop Census
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Selected tables
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Age by Sex; soon …
Trav
el to
Wor
k
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35
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37
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39
40
41
42
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Counts: People by City of usual residence,
Main Means of Travel to Work: 2006 Census
0 50,000 100,000
Worked at Home
Did Not Go To Work Today
Drove a Private Car, Truckor Van
Drove a Company Car,Truck or Van
Passenger in a Car, Truck,Van or Company Bus
Public Bus
Train
Motor Cycle or Pow erCycle
Bicycle
Walked or Jogged
Other
Not Elsew here Included
Manukau City
Auckland City
Waitakere City
North Shore City
Travel to work in the four Auckland cities
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Travel to work in Kapiti and Wellington
0%
10%
20%
30%
40%
50%
Worked atHome
Did Not GoTo WorkToday
Drove aPrivate Car,Truck or Van
Drove aCompanyCar, Truck
or Van
Passengerin a Car,
Truck, Vanor Company
Bus
Public Bus Train Motor Cycleor Power
Cycle
Bicycle Walked orJogged
Other NotElsewhereIncluded
Kapiti Coast District
Wellington City
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Table Builder: Datasets on Area Units:Population: Census 2006 vs
Population: Census 2001for Area Units of Waitakere City
0
2000
4000
6000
8000
0 2000 4000 6000 8000
Sturges North
Here's data for 10 Area Units:Area Unit Tot01 Tot06Sturges North 2283 5772Kingdale 3480 3537Fairdene 4410 4554Whenuapai West 1836 1842Herald 1656 1698Hobsonville 3342 3378Westgate 705 1092Royal Road West 2424 2664West Harbour 4569 4932Lucken Point 4656 5238
At this pointthe screen-shotsstop.But there’s a2-slide summary …
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www.stats.govt.nz for schools: short guide: p1Schools Corner SURF (No. 2) About the data source | The dataset | Activities
(copy the dataset and paste into your spreadsheet) StatZing! (the latest Activities) Find by …(find old StatZing!s etc)Table Builder 2006 Population Census Selected tables Travel to Work Expand (find the Areas you want)
Tick (use the ticks above and to left) Click the Table icon Actions, download to XL format (then copy and paste into your spreadsheet package) Age by Sex for 1996, 2001, 2006 (then as above)
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www.stats.govt.nz for schools: short guide: p2Infoshare Browse Work, Income and Spending Linked Employer-Employee Dataset Age and ANZIC96 (ANZ Industry Classification 1996) Select a few items, and for Time, Select All Go Pivot clockwise, to get data into a column Save as xls (copy the dataset and paste into your spreadsheet)Releases by Title (Takes you to Hot Off The Presses) NZ Income Survey NZ Income Survey; June 2008 (then explore these:) Highlights|Commentary|Technical notes|Erratum|Tables QuickStats about a Place(and also see QuickStats about a Subject, and NZ in Profile) Place List (and find your suburb) (and use the 12 tabs).
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What Statisticians do all day: an eg:The new Immigration Survey:
Pop: 36,620 approved immigrants in 2004Sample: 7,125 of them
We find Estimates (via ‘resampling’) with Sample Errors (= half the confidence interval)
Immigration survey: Labour Force ActivityLabour force status:Employed Looking for work
Immigration approval category Number Samp err Number Samp errSkilled Primary Applicant 11,630 510 220 90Skilled Secondary Applicant 5,130 350 410 130Business 1,210 100 40 30Family partner 4,770 150 240 80Pacific 1,120 160 70 10Notes: This is an example: values are not necessarily the actual ones. table is incomplete Samp Err is sample error: approximately 2 times the standard error found by jackknife. Number is the estimate, from the sample, o of the total number of people in the cell, for the population studied. The confidence interval for the estimate is: Number ± Sample error.
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Sample Error vs Estimate:
Sample Error vs Estimatefor cells from a LISNZ table
jackknife
0
100
200
300
0 1000 2000
Hmmmmmm: what does that show?
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Sample Error (up) vs Estimate (across):Sample Error vs Estimatefor cells from a LISNZ table
jackknife, binomial 1
0
100
200
300
0 1000 2000
Sample error has lots of variation: Can we explain some of it? How? What function might it fit? For the lower (blue) points, what did we forget?
Standard Deviationfrom binomial model = √ (p (1-p) N)
Sample Error fromthe data by Jackknife(ie resampling)
For cells from the Immigration Survey NZ
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Some consultation:
We asked Pat: You need to multiply by the 2 value:Sample Error = z * Standard Error = 1.96 * Standard Error
They forgot to multiply by 2
(or 2 ish)
Why are they so dumb in Wellington??
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Sample Error vs Estimate:
Sample Error vs Estimatefor cells from a LISNZ table
Jackknife, binomial 2
0
100
200
300
0 1000 2000
Hmmmmmm: how does that look?
Sample Error fromthe data by Jackknife(ie resampling)
Sample Errorfrom binomial model = z * √ (p (1-p) N)
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To confidentialise, we added noise: ± 4
Sample Error vs Estimatefor cells from a LISNZ table
jackknife
0
100
200
300
0 1000 2000
Noise fromconfidentialising is about this big:
Noise from samplingvaries, but is this big
Does the noise from confidentialising matter?
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What do we do all day?
In a Stats office In a Stats classroom
Find a problem that mattersFind some Data (Evidence)Talk, scratch headsDo some graphsTry models using MathsMake mistakesConsult with wise headsDo more graphsMake decisionsCommunicate results in: words, numbers, graphs
Find a problem that mattersFind some Data (Evidence)Talk, scratch headsDo some graphsTry models using MathsMake mistakesConsult with wise headsDo more graphsMake decisionsCommunicate results in: words, numbers, graphs
We hope you enjoy statistical discovery as we do!!
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Gender Balance in Waitakere:
Females vs Males for Area Units of Waitakere Cit
2006 Census
0
1000
2000
3000
0 1000 2000 3000
Y+X line
Herald
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The Maths and Stats teacher’s vital role:If the next cohorts of adults
can handle statistical evidence and thinking:That’ll be nice for Statistics NZ!
which produces: social, economic and environmental stats
That’s utterly essential for solutions to NZ’s and the Earth’s challenges.
Enjoy!!