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Intro to Statistics with R: Introduction
Types of variables
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Intro to Statistics
! Nominal
! Ordinal
! Interval
! Ratio
Types of variables
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Intro to Statistics
Nominal variables
!
Used to assign individual cases to categories
! DataCamp students come from many diff erent countries
! Country of origin is a nominal variable
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Intro to Statistics
Ordinal variables
!
Used to rank order cases
! Countries may be ranked according to overallpopulation
! Ranking is an ordinal variable
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Intro to Statistics
! Used to rank order cases where the distance, orinterval, between each value is equal
! Each country has a longitude and latitude
! Longitude and latitude are interval variables
Interval variables
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Intro to Statistics
Ratio variables
!
Same as interval variables but have a “true zero”
! Population (Population of 0 = extinct)
! Temperature °K (the Kelvin scale)
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Intro to Statistics with R: Introduction
Let’s Practice!
8/17/2019 Introduction to Statistics with R
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Intro to Statistics with R: Introduction
On the Theory ofScales of
Measurement
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Intro to Statistics
Types of variables
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Intro to Statistics
Race results
2:34:01
2:34:03
2:34:09
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Intro to Statistics
Types of variables
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Intro to Statistics with R: Introduction
Let’s Practice!
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Intro to Statistics with R: Introduction
Quick summary
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Intro to Statistics
Types of variables
!
Independent vs. dependent variables! Vaccine trial example
! Independent = treatment (nominal)
! Dependent = disease rate (ratio)
i i
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Intro to Statistics
Discrete vs. continuous
Variable Type Discrete or Continuous?
Nominal
Ordinal
Interval
Ratio
Discrete
Discrete
Continuous
Continuous
I S i i
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Intro to Statistics
Summary
!
Know your variable types!! Nominal
! Ordinal
! Interval
! Ratio
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Intro to Statistics with R: Introduction
Congratulations!
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