Descriptive statistics

• What is the mean?

  The average Of a set of data
• How to work out the mean?

  add All the numbers together then divide By how many numbers there are
• Strength of using mean.

  Includes all scores in data

  More representative of data set
• Weakness of using the mean.

  Easily distorted by extreme values

  Anomalies
• What is mode?

  The Most frequently occurring value in the dataset
• Strength of mode

  Useful when the mode is the only usable measure
• Weakness of using the mode.

  Too narrow

  There can be several modes or no mode at all
• what is the median?

  The middle value when the values are ordered highest to lowest.
• Strength of using the median.

  Not affected by extreme scores
• Weakness of median

  Less precise than mean

  It doesn’t consider all values in dataset
• What type of data is mean

  interval data
• What type of data is mode

  Ordinal and nominal data
• What type of data is median

  Internal and ordinal data
• What is interval data

  objective, equal intervals between units

  Time and distance can be quantified and ranked
• What is ordinal data

  Subjective, in order, not a univeral measure, categorised and ranked
• What is Nominal data

  Data that comes from categories
• what is the range?

  Highest- lowest number in a data set
• What is standard deviation?

  The spread of scores around the mean
• Strength of range

  Easy to calculate
• Weakness of range

  If the highest or lowest value is extreme it isn’t reflective of the data set.
• strength of standard deviation

  a sensitive and precise measure of dispersion.
• weakness of standard deviation

  Time consuming and more complex to calculate