Measures of central tendency | Mean | Total of values divided by the number of values. | Describe all responses with the average value. |

Median | Arrange all values in order and determine the halfway point. | Determine the middle value among all values, which is important when dealing with extreme outliers. |

Mode | Examine all values and determine which one appears most frequently. | Describe the most common value. |

Measures of variability | Variance | Calculate the difference of each value from the mean, square this difference score, sum all of the squared difference scores and divide by the number of values minus 1. | Provide an indicator of spread. |

Standard deviation | Square root of variance. | Give an indicator of spread by reporting on average how much values differ from the mean. |

Range | The difference between the maximum and minimum value. | Give a very general indicator of spread. |

Frequencies | Count the number of occurrences of each value. | Provide a distribution of how many times each value occurs. |