POL242Y5 Lecture Notes - Lecture 6: Univariate, Central Tendency, Descriptive Statistics
Document Summary
3 types of univariate descriptive statistics: distribution (how many cases take each value?) (how many students got an a?, central tendency (most typical value) (middle, dispersion (how much do the values spread out?) Shows the number of cases in each category of the variable. Displays the frequency with which each value occurs. Most typical value, the value that best represents the entire distribution. Mean, median and mode: mean= average (sensitive to outliers) (can only use with interval measurements, median= middle value, half above it, half below it (only ordinal and interval, mode= most common value (applies to all variables) Mean= sum of all values / number of cases. Median= put values in order, median is the middle. Interquartile range= q3-q1 (how far apart is the top 25% from the bottom 25%) Central tendency: interval= mean, median, ordinal= median, mode, nominal= mode. Dispersion: interval= standard deviation, ordinal= quartiles, nominal= variation ratio.
