Ratio e'g', lengths, weights, volumes, capacities, rates:

1
What are the Levels of Measurement?

• Ratio (e.g., lengths, weights, volumes,
  capacities, rates)
• Different categories
• Rankable categories
• Constant equal-sized Intervals
• Absolute Zero (physical significance, the zero
  actually signifies something) (e.g., temperature
  in Kelvin, time)
• Interval (temperature on Celsius and Fahrenheit,
  age)
• Different categories
• Rankable categories
• Constant equal-sized Intervals (can be expressed
  numerically)
• Ordinal (e.g.., dominance hierarchy)
• Different categories
• Categories are rankable
• Nominal (a.k.a. attributes)
• Different categories (e.g.., sex, species,
  phylum, location)

2
What are the Levels of Measurement?
Ratio

• (e.g., income, weights, volumes,
  capacities, rates)
• Different categories
• Rankable categories
• Constant equal-sized Intervals
• Absolute Zero (physical significance) (e.g.,
  temperature in Kelvin, time)
• construct a meaningful fraction (or ratio) with a
  ratio variable

Interval

• (temperature on Celsius and
  Fahrenheit)
• Different categories
• Rankable categories
• Constant equal-sized Intervals
• can be expressed numerically
• the distance between attributes does have meaning

Ordinal

• (e.g.., education attainment, class
  status)
• Different Categories
• Categories are rankable (attributes can be
  rank-ordered)
• Intervals are NOT equal-sized
• But is distance from 0 to 1 same as 3 to 4?
• Distances between attributes do not have any
  meaning.
• We don't assume the value of 2 means that
  sophomores are twice something than freshman are.

Nominal

• (e.g.., sex, ethnicity, agency,
  location)
• Different Categories
• numerical values just "name" the attribute
  uniquely
• NOT Rankable
• We don't assume that higher values mean "more" of
  something and lower numbers signify "less".

3
Presentation of Entire Distribution of a Variable
4
Central Tendency and Dispersion
5
Central Tendency and Dispersion