PSY201H1 Chapter Notes - Chapter 4: Standard Deviation, Squared Deviations From The Mean
Document Summary
Standard deviation - most commonly used and the most important descriptive measure of variability. Uses the mean of the distribution as a reference point and measures variability by considering the distance between each score and the mean. Provides a measure of the standard, or average, distance from the mean, and describes whether the scores are clustered closely around the mean or are widely scattered. Process: determine the deviation, or distance from the mean, for each individual score, the deviation for each score is the difference between the score and the mean. There are 2 parts to the deviation score: the sign (+ or -) and the number. The sign tells the direction from the mean; whether the score is located above or below the mean: to compute the mean, you add up the deviation scores and then divide by n (number of scores) The deviation scores add up zero because the mean serves as a balance point for the distribution.
