STANDARD DEVIATION

• WHAT DOES THE STANDARD DEVIATION TELL US?

  how far scores deviate from the mean
• LEVEL OF MEASUREMENT OF STANDARD DEVIATION?

  interval
• STRENGTHS OF STANDARD DEVIATION?

  • more precise
  • includes all values within final calculation
  • considers distance of each score from mean (not just distance between highest and lowest)
• WEAKNESSES OF STANDARD DEVIATION?

  • can be distorted by single extreme value
  • only used if you have a mean value
  • cannot be used for ordinal data