PSYC 2017 : 2017 Test 3
Document Summary
Descriptive statistics goal = to describe sample data. Mode most common score (least useful) distribution of scores. (contrasted w/ inferential stats, where the goal is to make inferences about populations from sample data) *central tendencies provide a single value that is typical of the. Standard deviation the average amount of variation from the mean frequency distributions listing of values in a data set along with their frequency. Provides a numerical value indicating the amount of variation in a group of scores r(squared) variation accounted for: range highest score minus lowest. Rarely used as a measure of variability: variance average deviation of the data values from their mean in squared, standard deviation squared root of variance. Even if population distribution is not normal, the sample average will be normal. Standard distribution (normal bell curve) (pic sampling distribution of the mean) z-scores make things standard across measures.
