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How to beat numbers and not let numbers beat you

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How to beat numbers and not let numbers beat you. Professor Charles Pattie. Why do we need numbers in social science?. Why do we distrust stats – and should we? Samples Why do we need numbers in social science? Context: how common or unusual are the things we study? - PowerPoint PPT Presentation
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How to beat numbers and not let numbers beat you Professor Charles Pattie
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Page 1: How to beat numbers and not let numbers beat you

How to beat numbers and not let numbers

beat youProfessor Charles Pattie

Page 2: How to beat numbers and not let numbers beat you

Why do we need numbers in social science?• Why do we distrust stats – and should we?• Samples• Why do we need numbers in social science?• Context: how common or unusual are the things we study?• Trend: are they increasing or decreasing?• Correlation: what are they related to, and what might influence them?

Page 3: How to beat numbers and not let numbers beat you

So why do we distrust stats?• Lies, damn lies and statistics?• Reliability: look at the question and the context• North Korean election 2014: 100% vote for Kim Jong-Un!

• Common sense rules: distrust clearly biased sources!

Page 4: How to beat numbers and not let numbers beat you

So why do we distrust stats?• Lies, damn lies and statistics?• Accuracy: how close can we get?• Sampling: a statistic is only as good as the sample it is based on• An analogy from cooking: tasting a small sample tells you what the whole dish

is like

Page 5: How to beat numbers and not let numbers beat you

Sampling in practice• The central limit theorem: why random samples ‘work’:

Average height (inches)Sample 1 Sample 2 Sample 3 Sample 4 Sample 5

Person 1Person 2Person 3Person 4Person 5

Average= #NAME? #NAME? #NAME? #NAME? #NAME?

Overall mean= #NAME?

Page 6: How to beat numbers and not let numbers beat you

Sampling in practice• Rules of thumb – when to trust a statistic. • Is the sample (more or less) random? (BIASED samples are bad news)• Is the sample large enough? (Think Goldilocks – not too large, not too small)• Does the question make real sense? (NB NOTHING to do with stats,

EVERYTHING to do with common sense!)• If there was an election tomorrow, which party would you vote for?• On which day of the year are people most likely to feel unhappy?• Do you think the local authority’s urban development policies are successful or not?

Page 7: How to beat numbers and not let numbers beat you

Context: Is crime out of control?• Are we in the grip of a crime explosion? Discuss!

Page 8: How to beat numbers and not let numbers beat you

Context: Is crime out of control?• The National Crime Survey suggests not:

Page 9: How to beat numbers and not let numbers beat you

Context: Is crime out of control?• But do we believe it? Some views from BBC News ‘comment’ section:

Page 10: How to beat numbers and not let numbers beat you

Context: Is crime out of control• Why are people so sceptical? Discuss!

• Anecdote versus evidence?

Page 11: How to beat numbers and not let numbers beat you

Trends: A world of numbers?• Seeing the wood for the trees: the value of careful presentation • e.g. the Gapminder project: http://www.gapminder.org/

Page 12: How to beat numbers and not let numbers beat you
Page 13: How to beat numbers and not let numbers beat you
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Page 16: How to beat numbers and not let numbers beat you
Page 17: How to beat numbers and not let numbers beat you

Correlations: A different example…

Page 18: How to beat numbers and not let numbers beat you

Correlations: UKIP and the 2014 Euro-election• Why did Nigel Farage launch UKIP’s 2014 European Parliament

election campaign in Sheffield?• Should David Cameron (and Ed Miliband and Nick Clegg) be worried

about the Euro-election?• Can numbers help answer these questions?

Page 19: How to beat numbers and not let numbers beat you

Why did UKIP launch their campaign here?• What do YOU think? Hunches? Ideas?• Might it have something to do with who votes UKIP?• Evidence from British Election Study Continuous Monitoring Survey

2004-2013 (reported in Rob Ford and Matthew Goodwin, 2014, Revolt on the Right, Routledge).

Page 20: How to beat numbers and not let numbers beat you

Why did UKIP launch their campaign here?

UKIP Conservative Labour Lib Dem0

5

10

15

20

25

30

35

40

45

50

Class and party support

Professionals Routine non-manual Working class

% su

ppor

t

Page 21: How to beat numbers and not let numbers beat you

Why did UKIP launch their campaign here?

UKIP Conservative Labour Lib Dem0

10

20

30

40

50

60

Education and party support

Left school aged 16 or under Left school aged 17 or 18 Left school aged 19+

% su

ppor

t

Page 22: How to beat numbers and not let numbers beat you

Why did UKIP launch their campaign here?

UKIP Conservative Labour Lib Dem0

10

20

30

40

50

60

Age and party support

Under 35 25-54 55+

% su

ppor

t

Page 23: How to beat numbers and not let numbers beat you

Why did UKIP launch their campaign here?

020406080

100

Age and party support

UKIP Eurosceptics Non-UKIP Eurosceptics Europhiles

% su

ppor

t

Page 24: How to beat numbers and not let numbers beat you

Why did UKIP launch their campaign here?• So… what do you think?

Page 25: How to beat numbers and not let numbers beat you

Correlation: lessons of 2014 Euro-election?• Should David Cameron (etc.) be worried?• Maybe! YouGov poll, 22-24 April 2014:

Page 26: How to beat numbers and not let numbers beat you

Correlation: lessons of 2014 Euro-election?

UKIP Labour Conservative Lib Dem0

5

10

15

20

25

30

35

40Vote intention

Euro-electionWestminster election

% su

ppor

t

Page 27: How to beat numbers and not let numbers beat you

Correlation: lessons of 2014 Euro-election?

UKIP Labour Conservative Lib Dem0

5

10

15

20

25

30

35

40Vote intention

Euro-electionWestminster election

% su

ppor

t

Page 28: How to beat numbers and not let numbers beat you

Why the switch?• Second order election theory: Euro-election a risk-free chance to vent

frustrations with government

Page 29: How to beat numbers and not let numbers beat you

But is the 2nd-order effect getting stronger (or are governments just getting less popular)?

1979 1984 1989 1994 1999 2004 200915

20

25

30

35

40

45

50

55

West-minster

% su

ppor

t for

incu

mbe

nt

1979 1984 1989 1994 1999 2004 200915

20

25

30

35

40

45

50

55

% su

ppor

t for

incu

mbe

nt

Page 30: How to beat numbers and not let numbers beat you

Moving on….• We’ve only scratched the surface of using numbers in social science

research.• Where next?• Getting good data

• Collect it yourself?• Data archives and official sources e.g. The UK Data Archive (

http://www.data-archive.ac.uk/)• More advanced techniques and software

• Good introductory guides include: Ian Diamond and Julie Jeffries, 2001, Beginning Statistics: A Guide for Social Scientists, Sage.

• If you learn one more advanced method, learn REGRESSION!• SPSS available ‘free’ to university students• Help at MASH

Page 31: How to beat numbers and not let numbers beat you

Moving on….• And with that – happy analysing!


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