Chapter 4: Variability

Question 1

What is variability?

Answer 1

Variability is a measure of the dispersion or spread of scores in a distribution and ranges from 0 to +∞.

Question 2

What are the three measures of variability?

Answer 2

Range, variance, standard deviation

Question 3

What is range?

Answer 3

The range is the difference between the largest value and smallest value in a data set.

Question 4

What is variance?

Answer 4

Variance is a measure of variability for the average squared distance that scores deviate from their mean.

Question 5

What is standard deviation?

Answer 5

The standard deviation is a measure of variability for the average distance that scores deviate from their mean.

It is calculated by taking the square root of the variance.

Question 6

What are degrees of freedom (df)?

Answer 6

The number of scores that are free to vary in a sample.

This term is placed in the denominator of the formula for sample variance.