Showing relevant statistics

Data Communication Concepts

Hadrien Lacroix

Curriculum Manager

Data storytelling road

  Puzzle piece with data word highlighted

Data Communication Concepts

Variations of data

  • Absolute
    • Difference between 2018 and 2017 sales
    • Absolute change and relative change depend on the quantity

bars showing absolute change of sales in two years

  • Relative

    • Percentage variation 2018 from 2017
    • Small numbers more significant than reality

bars showing relative change of sales in two years

Data Communication Concepts

Variations of data

 

Absolute

Graph showing two barplots with no difference

 

Relative

Graph showing a barplot with one bar higher than another one

Data Communication Concepts

Ratio

  • Quotient of two variables

    • Revenue per customer (total product revenue/number customers)

  • Normalize values = better comparisons

bars showing revenue per customer for chocolate and chips

Data Communication Concepts

Aggregates

  • Representative value:
    • Totals / counts
Data Communication Concepts

Aggregates

  • Representative value:
    • Totals / counts
    • Mean
  • Average units sold per year

bars showing mean

Data Communication Concepts

Aggregates

  • Representative value:
    • Totals / counts
    • Mean
    • Median
  • Median price

boxplot showing median price for two products

Data Communication Concepts

Aggregates

  • Representative value:

    • Totals / counts
    • Mean
    • Median

  • Mean can be misleading (outlier)

  • Distribution of the data
  • Example:
    • 2019 US average salary: $51,916.27
    • 2019 US median salary: $34,248.45
Data Communication Concepts

p-value

What is p-value?

  • Convention:
    • Value less than 0.05: statistical significance
    • Values close to 0.05: weak indicator

What is it not?

  • Not proof of evidence:
    • Reject our hypothesis, but not that is false
  • Consider alternatives or complementary metrics
1 P-Values: Misunderstood and Misused. Front. Phys. 2016.
Data Communication Concepts

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Data Communication Concepts

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