Basic Principles - Statistics

Question 1

What is a deviation score?

Answer 1

The distance between a raw score and the mean

Question 2

What is the Sum of Squared deviations?

Answer 2

The total (sum) of deviation scores (X-M) squared.

Also expressed as Sum (X - M) 2 (or X-U if using population mean)

Question 3

What is variance?

Answer 3

The average squared distance from the mean.
Divide sum of squares by sample number (population, or by n-1 for a sample)
Obtained by SS2/N (at a population level)
Obtained by SS2/n - 1 (at a sample level)

Question 4

What is standard deviation?

Answer 4

Measure of the average distance from the mean (cf. ave. squared distance which is variance)