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Globalisation

Geographical skills: statistics, data and research ethics

  • 3 things to know
  • Papers 2 and 3

Overview

The skills examined across every topic: null hypotheses and significance, t-tests and a worked chi-squared test, Lorenz curves and the Gini coefficient, logarithmic scales, kite and dispersion diagrams, coding, research ethics and big data.

What you need to know

Answer each one before you reveal it.

Your recallNot started
Process

How is a logarithmic scale read?

Process

Two samples of 10 have means 12.0 and 9.5 with standard deviations 2.0 and 2.5. Is the difference significant at p = 0.05 (critical value 2.10, 18 degrees of freedom)?

Process

How are expected frequencies calculated for a chi-squared contingency table?

Questions from this subtopic

Each one with the model answer underneath.

  1. 1

    What is a null hypothesis, and what significance level is usually used?

    Model answer

    A statement that there is no relationship or difference between the variables; geographers usually reject it if the probability that the result arose by chance is below 5% (p = 0.05).

  2. 2

    When is a t-test used, and what does it test?

    Model answer

    To test whether the means of two samples of interval data, which are roughly normally distributed, are significantly different, by dividing the difference between the means by their combined standard error.

  3. 3

    When is a chi-squared test used, and how is it calculated?

    Model answer

    To test whether observed frequencies in categories differ significantly from expected frequencies: χ² = Σ(O − E)²/E, with expected frequencies usually the total divided equally among the categories.

  4. 4

    Sixty pebbles are classified into three shape categories, with 30, 18 and 12 observed. Test whether they differ from an even distribution (critical value 5.99 at p = 0.05, 2 degrees of freedom).

    Model answer

    Expected frequencies are 20 each. χ² = 100/20 + 4/20 + 64/20 = 8.4, which exceeds 5.99, so the null hypothesis of an even distribution is rejected.

  5. 5

    How is a Lorenz curve plotted and a Gini coefficient interpreted?

    Model answer

    Cumulative percentage of income is plotted against cumulative percentage of population, poorest first; the further the curve bows below the line of equality, the greater the inequality. The Gini coefficient is the area between the line and the curve divided by the whole area under the line, from 0 (equality) to 1.

  6. 6

    How is a logarithmic scale read?

    Model answer

    Each major division represents a tenfold increase, so equal distances show equal ratios rather than equal amounts; a value halfway between 100 and 1,000 is about 316, not 550.

Other ways to work this

The same content, four other ways.

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Six ways to work the same material.

1Closed book
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Answer cold, learn it, then prove it stuck. Levo tracks the jump between your first attempt and your last.

Tectonic Processes and Hazards
Glaciated Landscapes and Change
Coastal Landscapes and Change
Globalisation

Cram a whole paper in one sitting

Sort every topic into what you know and what you do not, then drill only the weak ones.

The British Raj in .
IndiaChinaFrance

Blank Blitz makes facts automatic

Rapid timed gap-fills on the terms and numbers you need to recall without thinking.

AAbout 95% of the park is designated wilderness with strict protection.
BThe valley allows roads, hotels and climbing.
CThe Hetch Hetchy valley was dammed in 1923 to supply San Francisco.

Build It gets the exam shape right

Assemble a full-mark answer from its marking points, in the order an examiner wants them.

Erosion means removal of material by marine processes.
TrueFalse

Test It catches misconceptions

Spot the fault in a statement. The traps are the mistakes students actually make.

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Brain Breaks between sessions

Short focus games to reset attention, so the next set lands better than the last.

Every question in Globalisation, on a schedule.

Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.

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