PS268 Lecture Notes - Lecture 2: Bar Chart, Frequency Distribution, Unimodality
Document Summary
A distribution in which the values of the dependent variable are tabled or plotted against their frequency of occurrence. How many times each score or value occurred in a set of data (a distribution of scores) Usually nominal or ordinal data: how many males, how many females in a class. Graphical representations of data: we can describe a set of numbers in pictorial form, graphical presentation to demonstrate data, describe what scores occurred, frequency of each score. Graph in which a rectangle is used to represent frequencies of observations within each interval: used when variable is continuous rather than categorical (variable is interval or ratio = score data, adjacent bars touch. Frequency polygon: replace skinny bars with a point over each score, then connect the points with straight line, then connect the line to the x axis. Distributions can be described with respect to 3 characteristics: shape. 2)measures of central tendency = level, location, average.
