PSY 4930 Chapter Notes - Chapter 3 and 5 (Salkind): Correlation And Dependence, Scatter Plot, Standard Deviation
Document Summary
Chapter 3 (salkind): vive la difference, understanding variability. Variability reflects how scores differ from one another. 7, 6 3, 3, 1 shows variability. 3, 4, 4, 5, 4 less variability but same mean as above. 4, 4, 4, 4 shows no variability. Becomes a measure of how much each score in a group of scores differs from the mean. 3 measures of variability are commonly used to reflect the degrees of variability, spread, or dispersion. Can be used to describe the characteristics of a distribution + show how distributions differ from one another. Is computed by subtracting the lowest score in a distribution from the highest score. Represents the average amount of variability in a set of scores. = sum of what follows = individual score = mean (cid:1866) = sample size. Unbiased estimate: a conservative estimate of a population parameter.
