Chapter 3: Understanding Variability

Question 1

Variablity

Answer 1

How much scores differ from one another or, put another way, the amount of spread or dispersion in a set of scores

Question 2

Range

Answer 2

The positive difference between the highest and lowest score in a distribution. It is a gross measure of variability. Exclusive range is the highest score minus the lowest score. Inclusive range is the highest score minus the lowest score plus 1

Question 3

Standard Deviation

Answer 3

The average amount of variability in a set of scores of the scores’ average deviation from the mean

Question 4

Mean Deviation

Answer 4

The average deviation for all scores from the mean of a distribution, calculated as the sum of absolute value of the scores’ deviations from the mean divided by the number of scores

Question 5

Unbiased Estimate

Answer 5

A conservative estimate of a population parameter

Question 6

Variance

Answer 6

The square of the standard deviation and another measure of a distribution’s spread or dispersion