StatMine – prototypeStatMineExploring official statistics

Martijn Tennekes, Edwin de Jonge, Jan van der Laan & Jessica Solcer

Statistics Netherlands (CBS)

Visweek 2013

StatMine, statistical goldmineEdwin de Jonge (@edwindjonge)Jan van der Laan, Jessica Solcer

Statistics Netherlands / CBSDutch Information Visualisation Event 2014, June 19, 2014

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Statistics Netherlands / CBS

- Creates and publishes official statistics on economics, demographics, health care and others.

- Since 1899

- Website: www.cbs.nl- Online DB: http://statline.cbs.nl (since 1997)

Why StatMine?

– Online StatLine contains more than one billion (109) facts‐ Policy makers‐ Journalists‐ Citizens‐ Enterprises‐ Economists‐ Social scientist‐ Historicians‐ etc

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Problem 1Numbers ≠ Information

1. Numbers ≠ Information

We know from a user study that:1. Many interesting patterns in StatLine are not

spotted by users

2. Many important topics in StatLine are scattered across multiple tables

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H1:Data analysis= Data insight

H1. Data insight

Goal of StatMine 0.1 was to provide more insight StatLine numbers by

• Presenting these facts visually and interactively

• We tested this succesfully on 4 “difficult StatLine tables.

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Bar chart

- compare

Line chart

- development

Bubble/scatter chart

- correlationMosaic chart

- structure

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Chart type – bar chart

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Small multiples?

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Demo

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StatMine 0.1 Results

Tested on 25 users:

Findings:- Test persons think that visualizing data

adds value (small multiples)- Data owners look at their data

differently- They want this tool to check their data

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Problem 2:Fragmented Information

2. Fragmented information

Most information in StatLine is fragmented:

‐ Energy consumption wrt economic growth‐ Perceived public safety wrt registered crime

– Users currently need to look into multiple tables and combine the information by hand. Gebruiker moet in meerdere tabellen kijken en informatie zelf combineren

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2. Merge data!

H2. Table joining

Goal StatMine 0.2: create more insight by:

- Letting users combine tables- Condition: share at least one

column/data dimension.- Tested on small set of tables.

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StatMine 0.2 Results

Test persons: 20 internal, 40 external (policy makers, journalists).

Findings:- External users enthousiast about

visual possibilities StatMine- Joining of data fills a user need.

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Problem 3Statistical numbers are uncertain

H3. Confidence intervals

– Al facts Statistics Netherlands have confidence interval

– European Statistics Code of Practice (12.2): ‐ “sampling and non sampling errors should

be systematically documented”

Goal StatMine 0.3:

Investigate how uncertainty in numbers can be presented understandable to users.

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Restricted to:‐ How do users interpret CI’s? And what does

that affect the interpretation of facts?‐ Do users need CI’s?

Assumption: ‐ For test data set of point estimate with CI

available

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User test (100+) with synthetic data shows that:

‐ CI’s improve validity of user statements (they are more correct)

User test CI’s

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– Prototype StatMine 0.3:‐ Show uncertainty in Line Charts‐ Bar Charts‐ Tested on 25 test persons.

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Line charts with uncertainty

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Bar charts with uncertainty

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StatMine 0.4

–Build on CBS open data API–Will be public–Currently in beta test, ETA (2014 Q3)

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Questions?

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