Graph Description Notes:

  • Context - Use variable/group names

  • Shape (Roughly symmetric, double peaked binomial, single peaked unimodal, right or left skew)

  • Outliers - Any unusual observations

  • Center - The average/typical values

  • Spread - Variability

  • If comparing, use comparative language for center/spread (higher, lower, etc.)

Center:

  • Median - the middle point if a distribution

  • Use with skewed data

Mean:

  • m = sum of terms/number of terms

  • Use with symmetric data

Variability:

  • Range = Maximum - Minimum

  • ‘The context typically varies by sx from the mean of x.’

Non-Resistant Measures:

  • Greatly affected by extreme values

  • Example: Mean, standard deviation, range