descriptive statistics

• 2 types of descriptive statistics?

  1. measures of central tendency - averages
  2. measures of dispersion - spread
• measures of central tendency?

  • mean
  • median
  • mode
• measures of dispersion?

  • range
  • standard deviation
• what does descriptive stats allow us to do?

  • describe & summarise quantitative data
• advantage using mean?

  • uses all values in data so its most powerful & sensitive measure
  • using every result
• disadvantage using mean?

  • can be distorted by extreme values (anomalies) which are much higher/lower compared to rest so its unrepresentative
• advantage using median?

  • unaffected by extreme values
  • easier to calculate than mean
• disadvantage using median?

  • only takes into account middle values
• advantage of mode?

  • unaffected by extreme values
  • easier to calculate than mean
• disadvantage using mode?

  • not useful in small sets of data or if there are too many modes
  • does not take into account other scores