PSYC 2017 : 2017 Exam 3
Document Summary
Chapter 7: summarizing and interpreting data using statistics. The goal of descriptive statistics is to describe sample data. Can be contrasted with inferential statistics where the goal is to make inferences about populations from sample data. A listing of values in a data set along with their frequency. Bar graph of frequency distribution: used with categorical variables, height of bar represents frequency of category, bars should not touch. Histogram: used with continuous quantitative variables, no space between bars. Line graphs: also used with quantitative variables, particularly useful for interpreting interactions. Scatterplots: depicts relationship between two quantitative variables, correlations. Provides a single value that is typical of the distribution of scores: mode, most frequently occurring value. Least useful measure of central tendency: median, middle score when numbers are in ascending or descending order, mean, arithmetic average, most commonly used measure of central tendency.
